The manifesto, officially launched by party leader Jeremy Corbyn in Bradford today, confirms a range of policies that featured in a leaked draft version that emerged last week, such as extending free childcare entitlement and preventing further cuts to youth centres and children's services.
But it also includes a fresh commitment to improve the way the children's care system works.
The manifesto claims that the Conservative government is "currently failing to develop a strategy for the wholesale improvement of the care system that delivers for all, not just those children being considered for adoption".
"We will promote the care and educational achievement of our most vulnerable children and increase support for children in kinship and foster care, and their families," the manifesto adds.
"It is important that other forms of care, such as kinship care and fostering, are not marginalised, as this will not result in the step-change we need to see in outcomes for looked-after children."
Labour has previously criticised the government "obsession" with adoption, claiming it is neglecting other forms of care.
But children's minister Edward Timpson has said that the notion that the government "only has eyes for adoption" within children in care policy is "not borne out by the facts".
The Labour manifesto also features a fresh pledge to extend so-called Staying Put arrangements, which allow young people to remain in foster care up to the age of 21, to support all children and young people in residential and other forms of care until they are 21.
The government is currently trialling Staying Close for children in residential care, which stops short of offering the same right to stay in care until they are 21 as those in foster care receive under Staying Put arrangements.
Staying Close enables young people leaving residential care to live near to, and retain links with, their children's homes.
The Labour manifesto confirms a number of policies that featured in a leaked draft version last week.
Labour will support further regulation of commercial fostering agencies, as well as commissioning a review on establishing a national fostering service.
It will extend the 30 hours of free childcare for all three- and four-year-olds due to be introduced in September, to all two-year-olds, and move towards making some childcare available for one-year-olds and extending maternity pay to 12 months.
Purnima Tanuku, chief executive of National Day Nurseries Association. said: "Labour's promise of free universal childcare from aged two is an ambitious pledge which would help millions of families across the UK.
"Childcare costs in Britain are among the highest in Europe so any help offered to parents will relieve the financial burden and encourage more parents into work.
"Research also shows that children who receive high-quality early learning will have the best life chances.
"But the current system is not working because it is chronically under-funded. Until this funding crisis is addressed, plans to increase beyond what has already been promised are overly ambitious."
Neil Leitch, chief executive of the Pre-school Learning Alliance, said that although it is positive to see the importance of quality early years care and education recognised in Labour's manifesto, experience has taught the sector to be sceptical of claims of fully-costed, fully-funded "free childcare" schemes.
"As we've seen with the existing 30-hour offer for working families, if such policies aren't adequately funded, many providers simply won't engage with them - our recent survey revealed that less than half of nurseries, pre-schools and childminders in England plan to deliver the current offer for three- and four-year-olds," he said.
"As such, as is always the case, the devil is in the detail. If Labour's policy costings are based on existing early years funding rates, which have long been insufficient, then this pledge will inevitably will be underfunded.
Labour has also said it will act to "insource" our public and local council services, and improve funding for local authorities.
"Labour believes in devolving power to local communities but that requires the necessary funding follows. You cannot empower local government if you impoverish it," the manifesto states.
"A Labour government will give local government extra funding next year. We will initiate a review into reforming council tax and business rates and consider new options such as a land value tax, to ensure local government has sustainable funding for the long term."