Parents who suffer the loss of a child under the age of 18 will be entitled to two weeks' bereavement leave from work, under what is known as Jack's Law.
The new legal right has been created in memory of toddler Jack Herd, from Stank near Barrow-in-Furness.
The 23-month-old died in a pond at his family home in 2010.
Video report by Rob Smith.
His mother, Lucy, campaigned for extended leave for grieving parents after Jack's father discovered he was only entitled to three days off work - one of which had to the funeral.
Ministers say the new law is a "fitting testament" to Lucy's campaigning. The new law will come into force from April.
"When I started this campaign 10 years ago after the death of my son Jack, I always hoped that a positive change would happen in his memory.