Proposed new legislation will entitle parents to two weeks' bereavement leave if they lose a child.
Grieving parents currently have no automatic right to time off, although employers are expected to grant "reasonable" leave in emergencies.
From 2020, it is hoped parents who lose a child will be able to request paid absence in England, Wales and Scotland.
Small firms would be able to reclaim the full cost from the government, with larger firms recouping about 90%.
The move follows a cross-party campaign by MPs for statutory bereavement leave for parents.
A private member's bill tabled by Conservative MP Kevin Hollinrake on the subject has won the backing of ministers and will be debated in the Commons for the first time next week.
Should the bill be approved, all parents in full-time and part-time employment with 26 weeks' continuous service would be entitled to two weeks' bereavement leave in the event of the death of a child under the age of 18.It will not apply to self-employed workers.
'Leading the way'
Announcing the move, Business Minister Margot James said parents going through the nightmare experience of seeing their child die deserved the full support of their employers.
"That is why the government is backing this bill, which goes significantly further than most other countries in providing this kind of workplace right for employees."
Mr Hollinrake welcomed the move, as did campaigners who said the commitment meant the UK would be "leading the way" in supporting families.
"Losing a child is one of the most devastating experiences that a parent can go through and it is vitally important that they are supported by their employer and not made to return to work before they are ready," said Francine Bates, chief executive of the Lullaby Trust, which supports bereaved parents.
Conservative MP Will Quince, who proposed a similar bill during the last Parliament, hailed the government's support for "world-leading workplace rights".
The Department for Business said small firms would be able to recover the cost in full while larger employers would be able to get "almost all of it back", expected to be about 92%.
Officials estimate the total cost to the taxpayer to be between £1.3m and £2m a year.
The new entitlement will not apply in Northern Ireland, where employment legislation is devolved....