- Video report by ITV News Correspondent Penny Marshall
Many of the victims were leaving the nearby Route 91 music festival.
Here is what we know about those who tragically lost their lives.
- Sonny Melton
Sonny Melton was the first of the victims to be named.
The 29-year-old died saving his wife Heather, who he had been married to for just over a year.
"He saved my life. He grabbed me and started running when I felt him get shot in the back," she told a local radio station.
"I want everyone to know what a kind-hearted loving man he was."
Mr Melton was from Big Sandy in Tennessee and worked as a nurse at Henry County Medical Center.
- Quinton Robbins
Quinton Robbins was a 20-year-old student at the University of Nevada-Las Vegas.
His aunt Kilee Wells Sanders confirmed the death of her nephew on Facebook calling him "the most kind and loving soul".
She added: "Everyone who met him, loved him. His contagious laugh and smile. He was truly an amazing person. He will be missed by so many, he is loved by so many.
"So many awesome talents. I can’t say enough good about this sweet soul. I, and your entire family will miss you so much everyday."
- Jordan McIldoon
Jordan McIldoon was a mechanic's apprentice from Vancouver, Canada who was just days away from his 24th birthday.
Festival-goer Heather Gooze posted on Facebook he died in her arms.
She wrote: "Friends and family, I am ok. I am right outside the festival grounds...I am with a young man who died in my arms!
"RIP Jordan McIldoon from British Columbia. I can't believe this just happened."
- Jessica Klymchuk
Jessica Klymchuk was in Vegas with her fiance when she was killed.
The Canadian mother-of-four was from Valleyview, north of Edmunton.
Edmunton Mayor Don Iveson confirmed her death and tweeted: "Our hearts are all broken. We will rally for Jessica's children and family."
- Denise Salmon Burditus
Denise Salmon Burditus was in Vegas with her husband Tony and posted this photo of them together moments before the gunman opened fire.
In a tribute on Facebook, Tony, who survived, said his wife had passed away in his arms.
"It saddens me to say that I lost my wife of 32 years, a mother of 2, soon to be grandmother of 5 this evening in the Las Vegas shooting.
"Denise passed in my arms. I LOVE YOU BABE."
- Lisa Romero
High school secretary Lisa Romero worked at Miyamura High School in Gallup, New Mexico.
Her cousin Ashley Romero described her as a "happy-go-lucky person who loved her kids and husband".
"For this to happen so senselessly is a heartbreaking day for us all," she added.
- Adrian Murfitt
Fisherman Adrian Murfitt, 35, who lived in Anchorage, Alaska, was at the music festival with his best friend when he was shot in the neck.
His friend wrote in a Facebook post: "Sadly he died in my arms. I don't really know what to say at this time."
- Angie Gomez
Angie Gomez was confirmed dead by her former high school.
Riverside Polytechnic High PTSA in California posted on Facebook: "We received word that 2015 alumnus Angie Gomez was involved in the Vegas shooting.
"We are heartbroken...she will always be loved and endeared by our Poly Family."
- Rachael Parker
Rachael Parker, a police records technician, died in hospital, the Manhattan Beach Police Department said.
Ms Parker was among four department employees who were attending the Route 91 Harvest Festival while off-duty. Another suffered minor injuries.
"She was employed with the Manhattan Beach Police Department for 10 years and will be greatly missed," the department said in a statement.
- Sandy Casey
Special educational needs teacher Sandy Casey, 35, was at the Las Vegas concert with her fiance and a friend, who were not injured.
Manhattan Beach Middle School, where she worked, paid tribute to her saying she was "loved by students and colleagues alike".
"She will be remembered for her sense of humour, her passion for her work, her devotion to her students, and her commitment to continuing her own learning and to taking on whatever new projects came her way.
"She has made a tremendous difference in the lives of her students and their families....her loss will be deeply felt," they said in a statement.
Her family is discussing setting up a scholarship in the teacher's name.
- Charleston Hartfield
Off-duty Las Vegas police officer Charleston Hartfield was also killed in the shooting.
The 34-year-old was known as a selfless, respected leader who brought out the best in the youth football team he coached, a father of one of Mr Hartfield's players said.
Troy Rhett, a friend of Mr Hartfield's through football, said he knew from social media that the police officer was attending the Sunday concert.
When he heard about the shooting, he texted him, hoping to learn Mr Hartfield was safe. He never heard back, and Mr Rhett said he later learned through another friend that Mr Hartfield had died.
Mr Hartfield, who also went by "Chuck" or "Charles" or even "Chucky Hart," was also a military veteran and leaves behind a son and a daughter, Mr Rhett said.
- Susan Smith
Married mother-of-two Susan Smith from Simi Valley near Los Angeles was confirmed to have been killed by the public information officer for the school district she had worked for since 2001.
The 53-year-old was described as "wonderful with the kids and the staff and was an integral part of the school community.
"She was the hub of everything that happened at the school.
"If a kid is sick, she's the one calling the parents and no matter how chaotic things got here, she was always smiling."
In a Facebook post, Vista Elementary School's Parent Teacher Association said: "Our hearts are full of sorrow for the passing of Susan Smith.
"She was a wonderful woman, an advocate for our children, and a friend. Our thoughts and prayers are with her family."
- Rhonda LeRocque
Rhonda LeRocque from Tewkesbury, Massachusetts, was at the music festival with her husband and six-year-old daughter, who both survived.
Her family described her as being "as close to perfection as possible".
- Dorene Anderson
Stay-at-home mother Dorene Anderson from Anchorage, Alaska, was also among the victims.
Friends from her hockey group, which was one of her passions, called her a "wonderful, generous person who was a friend to many."
- Christopher Roybal
Christopher Roybal was a Navy veteran who survived a tour of Afghanistan but died in the shooting.
He was his mother at the concert, who confirmed his death on Facebook.
Describing it as the "saddest day of my life", Debby Allen wrote her "heart is broken in a billion pieces".
"For anyone who knew the relationship we shared, you then know we were best friends. I will forever miss my Munchkin", she added.
- Austin Davis
Austin Davis' long-term girlfriend Aubree Hennigan confirmed her boyfriend was one of the victims of the Las Vegas shooting.
The 29-year-old California resident was a pipe fitter for UA Local 364.
In a Facebook post, Hennigan said: "Tonight we lost an amazing man. Austin, my love, I can't believe this happened. You didn't deserve this."
- Jenny Parks
Jenny Parks was a kindergarten teacher at the Lancaster School District in California.
Mrs Parks was attending the Route 91 festival with her husband, Bobby, who it is also believed was shot, but his injuries are not thought to be life-threatening.
Mr Parks' uncle Steven McCarthy said: "She was truly one of the most loving people you could ever hope to meet. She always went out of her way to help anybody."
- Jennifer Irvine
San Diego attorney Jennifer Irvine was also among the victims.
Friend Kyle Kraska wrote on Facebook: "My heart is broken. Jennifer Irvine, you are a shining light that will not be extinguished by a gutless coward with a gun.
"You brought so much joy to others, including me. You left this world singing & dancing, but far too soon.
"I will never forget you or any of the happy moments we shared. You made this world a better place simply by your presence. So long, my dear friend."
- Bailey Schweitzer
Bailey Schweitzer had spoken to weeks about going to the festival where she tragically lost her life.
The 20-year-old receptionist's death was confirmed by her employer Infinity Communications, who held a candle-lit vigil for her after finding out about her passing.
In a Facebook post, the company said: "We are saddened today as Bailey was always the ray of sunshine in our office on a cloudy day.
"No one could possibly have a bad day when Bailey was around. If you have ever called or visited our office, she was the perky one that helped direct you to the staff member you needed."
- Neysa Tonks
Mother-of-three Neysa Tonks was shot and killed in Las Vegas as she attended the music festival with her boyfriend.
Ms Tonks was reportedly shot during the first round of fire from a nearby hotel.
Her brother Cody Davis said: "My older sister was murdered last night. Our hearts are devastated. The sadness is too much to understand. I don't know what to say or what to do.
"I miss you Neysa. You are a great mom, sister and friend. We are trying to understand why and how this could happen. We are trying to process this situation but it still feels like a nightmare."
- Jack Beaton
Californian Jack Beaton died while trying to protect his wife during the shooting.
His son Jake Beaton said: "Lost my best friend. I love you so much more then you could ever imagine. Please watch over our family. You will forever be remembered as our hero!"
- Michael Anderson
Victim Michael Anderson was "everything a woman could want", his wife Bianca Acosta said.
"The thing about my love story with Michael is that it has been ever lasting since the moment we locked eyes.
"I have been crazy in love with this man since I was fifteen. I never felt so much love and adoration. He was everything a woman could want and need in a man," Acosta wrote on Facebook.
- Thomas Day Jr
Builder Thomas Day Jr was the "best dad", his own father said.
Day Snr confirmed his son died at the festival, which he was attending with his four children.
“He was the best dad. That’s why the kids were with him. They’re crushed," Day Snr told the Los Angeles Times.
- Kurt von Tillow
Kurt von Tillow from Cameron Park, California, was also killed at the Route 91 festival.
Two more members of his family were injured in the shooting.
Mark Carson, Von Tillow's brother-in-law told KCRA: "My brother-in-law was the most patriotic person you've ever met.
"Guarantee you, he's covered in red, white and blue right now, with a Coors Light in his hand, smiling with his family and listening to some music."
- Hannah Ahlers
Mother-of-three Hannah Ahlers was in Las Vegas with her husband Brian and two other couples when she was killed.
Friend Hannah McFayden wrote on Facebook said: "Our hearts are broken for Brian Ahlers and his family ... a beautiful mother/wife a kind soul with a laugh that was contagious !! was taken from the.
"Last night my sister and brother Elliott lost there best friend .life will not be the same with out you .. we love you Hannah Ahlers your Smile will carry with us."
- Carrie Barnette
Carrie Barnette was celebrating a 30th birthday at the Route 91 Harvest festival when she was killed by a gunman in Las Vegas.
Ms Barnette had worked at Disney World for over a decade.
Friend Destiny Calderon wrote: "You were a beautiful soul that would give so much in this world. I treasure all the memories we had.
"You will be missed. When I see hummingbirds I will think of you. Heaven has gained an angel."
- Melissa Ramirez
Melissa Ramirez worked for the American Automobile Association.
Her cousin wrote on Facebook: "My heart is so heavy,, I keep thinking of you and the tears won't stop.. I know your in paradise now with mami papi,your dad joe abel n frankie and erbody else.
"No more pain nomore meds.. Your dancing in the sky.. So today we share this day together,, just like old times..
- Calla Medig
Canadian Calla Medig was visiting Las Vegas when she was killed at the Route 91 festival.
Friend Cassandra DuChene wrote: "One of the most amazing people I have ever met was taken too early today... to Calla Medig ‘s family and friends my heart is with you and may she never be forgotten."
- Cameron Robinson
Cameron Robinson was with his boyfriend Bobby Eardley in Las Vegas.
The 28-year-old worked in the city of Las Vegas.
Will Dover wrote on Facebook: "He was my first boyfriend in Vegas...sweet...funny.... charming...I love you Cameron Robinson R.i.p."
- John Phippen
John Phippen was at the music festival with his son Travis when he was shot.
Medic Travis helped save 14 people at the scene but sadly he could not save his wounded father.
Mr Phippen ran a home remodelling and repair company in Valencia, California.
- Dana Gardner
Dana Gardner worked for the San Bernardino County County Clerk’s office.
The 52-year-old's daughter Kayla said: "We are devastated and still in shock trying to comprehend what happened last night."
- Chris Hazencomb
Chris Hazencomb, from California, had been waiting with a friend to see Jason Aldean when he was fatally injured.
Friend Nikki Torres wrote: "He was a very kind man that everyone loved dearly. He will be missed by many.
"As we are dealing with this loss, I am also thinking of his kind mom and the struggles she is about to go through."
- Steve Berger
Steve Berger had been in Las Vegas celebrating his 44th birthday with friends.
A father of three young children, Berger worked as a financial advisor in Minnesota.
A friend who had been with him at Route 91 described Berger as "charismatic, full of energy and breathed life into every room".
- Heather Alvarado
Mum-of-three Heather Alvarado, 35, from Utah, went to the Route 91 festival with her daughter.
Her daughter was not injured in the shooting but sadly Heather never returned.
Her husband Albert is a firefighter in Cedar City and the fire department said both of them were "part of the family".
"She will be missed," they added in a statement.
- Denise Cohen
Mother-of-two Denise Cohen had been looking forward to attending the music festival "for weeks", but never made it home.
She was with her boyfriend Derrick 'Bo' Taylor, who also died in the shooting.
Her son Jeff paid tribute to her saying: "Our mother was such a strong, beautiful and happy woman who made a difference to the lives of everyone she knew."
- Derrick 'Bo' Taylor
Californian corrections officer Derrick 'Bo' Taylor was with girlfriend Denise Cohen (above) when they were both killed at the music festival.
The couple were staying in a hotel there but never checked out and missed their flight home. They both have two grown sons.
- Stacee Etcheber
Stylist Stacee Etcheber was a mother and wife of a San Francisco police officer.
She had been at the music festival with her husband Vinnie but the pair became separated in the chaos.
Family and friends said they were "heartbroken" at her death.
- Jordyn Rivera
Jordyn Rivera was a fourth-year student at California State University studying health care management.
The 21-year-old had gone to the festival with her mother because she loved country music.
Friends said they were "numb" at the news of Jordyn's death.
- Kelsey Meadows
Teacher Kelsey Meadows, 28, was described as "smart, compassionate and kind" by Taft Union High School principal, Mary Alice Finn.
In a statement, Ms Finn said: "She had a sweet spirit and a love for children.
"Words cannot adequately capture the sorrow felt by her students, colleagues and friends in learning of her passing."
Her brother, Brad Meadows, posted on his Facebook page: "So it is with an absolutely shattered heart that I let everyone know that Kelsey did not survive this tragic event.
"Please keep my family in your thoughts and prayers as we try and move past this horrible time."
- Tara Roe Smith
Mother-of-two Tara Roe Smith, 34, of Alberta, Canada, went to Las Vegas with her husband Zach for a weekend getaway.
Her aunt, Val Rodgers, said: "She was a beautiful soul. She was a wonderful mother and our family is going to miss her dearly."
Ms Smith, the mother of two young boys, lived in Okotoks.
- Bill Wolfe Jnr
Bill Wolfe Jnr was in Vegas celebrating his 20th wedding anniversary with his wife Robyn when he was killed.
Bill was a youth wrestling and Little League baseball coach from Pennslyvania.