London's Night Tube began on Friday with Sadiq Khan on board the first departure.
Roughly 50,000 people are expected to use the Night Tube service each weekend, with the number growing to 200,000 by the Autumn when the service extends to the Northern, Jubilee and Piccadilly lines.
The mayor chatted to passengers on the historic evening, telling one: "You're making history".
Mayor of London Sadiq Khan has urged the public to remain "calm and vigilant" as police investigate whether a knife attack that left one woman dead and five others injured was terror-related.
Mr Khan said his "heart goes out to the victims of the incident in Russell Square and their loved ones".
Mayor of London Sadiq Khan has said London is "united" with Nice in grief following the "unspeakable attack" which has left at least 84 people dead.
London Mayor Sadiq Khan today warned voters that "out is out" and that there would be no going back from a vote to leave the European Union.
Speaking alongside Labour Leader Jeremy Corbyn, First Minister of Wales Carwyn Jones AM and Leader of Scottish Labour, Kezia Dugdale MSP, at a Labour In for Britain event in Kings Cross, London, Mr Khan said that the outcome of the referendum was a decision that would affect the UK "for decades to come".
Urging the electorate to vote for the UK to remain in the EU, the former Labour MP warned: "This is the fight of our lives".
Mr Khan added that working together as part of the EU, the UK would be "stronger, safer, and better off".
London Mayor Sadiq Khan has met with Labour leader Jeremy Corbyn in public for the first time after a weekend of contrasting election fortunes.
While Mr Khan enjoyed electoral success in the capital, Mr Corbyn oversaw less encouraging results for his party in the UK's "Super Thursday" elections.
New London mayor Sadiq Khan has said that he felt disappointed by how the Conservative campaign was run during the mayoral election and referred to the tactics used as "nasty".
Speaking on the BBC's Andrew Marr show he said: "I was disappointed that the Conservative party chose to have a campaign that was nasty, that was negative and that was divisive."
Sadiq Khan's first public engagement since being installed as Mayor of London on Saturday will be at a Holocaust Remembrance Day ceremony.
Mr Khan will appear at the event in Barnet, north London, alongside a number of prominent figures in the Jewish community to commemorate the millions slaughtered during the Nazi genocide.
Up to six millions Jews are known to have been killed in the Holocaust during the Second World War.
The appearance comes after Mr Khan took a strong stance against anti-Semitism during the racism scandal which engulfed the Labour Party in recent weeks.
Newly elected London mayor Sadiq Khan has hailed the announcement that he had won the capital's mayoral race as a "victory for hope over fear and for unity over division".
In a message of thanks posted to supporters on his Twitter page in the early hours of Saturday morning, shortly after he broke the Conservatives' eight-year hold on City Hall, Khan also hailed the win as "an amazing victory".
He also linked to his website where his full message of thanks was printed: