An interactive map, which was updated this week for half term, lists hundreds of the latest projects - from computer coding to theatre clubs - that he hopes will divert young people from crime.
Many of the activities are supported by the mayor's Young Londoners Fund, and are available across the capital, but especially in the 10 boroughs most affected by knife and violent crime, including Islington, Hackney, Croydon, Newham, Lambeth, Southwark and Lewisham.
From May, the bidding will open for organisations to a share in the next wave of funding. Some £15m will be available to youth organisations, charities and schools, from the replenished £45m fund.
Saddiq Khan said: "Massive reductions in government funding have caused crippling cuts to youth services and policing and there's no denying that this has contributed to a rise in violent crime."
A statement from the mayor's office said the fund had invested £20.5m in 179 projects, benefitting more than 63,000 young people in London.
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The interactive map explains how the capital's young people can use the projects to gain skills that are "designed to help them reach their full potential", according to a statement from the mayor's office.
The mayor said that £39m has been cut from youth services since 2011, resulting in a 44 per cent cut for local authorities' youth service budgets and causing 81 youth centres to close.
According to official statistics, there is an upward trend in knife crime among young people.
In 2016/17 children and young people were involved in 4,000 crimes involving knives or offensive weapons - an 11 per cent increase from five years earlier. One in five perpetrators was aged under 18 - the highest number for seven years.
Meanwhile, this month the Home Office announced a youth advocates scheme to equip local role models with skills to tackle the problem.