The so-called "London Living Wage" has been increased by 25p an hour to £7.85.
The minimum pay per hour pay now stands £2 higher than the national minimum wage of £5.80 per hour.
Mayor Boris Johnson said the rise was needed to "combat poverty" and ensure that "people are better off in work than out of work".
About 100 companies and local authorities offer the London Living Wage to their workers and four new firms have also signed up.
Deloitte, Nomura, Prudential and Standard Chartered have now joined the group, the mayor said.
'No poverty wages'
Mr Johnson said: "The capital relies on the work of many who carry out the city's essential functions on a daily basis - from office cleaners to care workers in social services.
"It is right that their skills and commitment to London's success are recognised, and one of the most fundamental ways of doing this is to ensure that all Londoners are paid properly.
"That means receiving at least the London Living Wage, which is designed to combat poverty and also ensure that people are better off in work than out of work."
The regional secretary of Trades Union Congress, Megan Dobney, said: "It makes sense that both private and public sector employers across the capital are seeing the Living Wage as a way to treat their staff well.
"There is no place for poverty wages in London."
The wage rate is a 3.3% rise on last year's figure and has increased by 17% since it was introduced five years ago.