But work is set continue at the delayed Bond Street station, which will not open with the other stations on the day.
TfL said work was progressing at Bond Street and the team were working hard to open the station to customers later this year.
The Elizabeth line was originally planned to open in December 2018 but the project faced numerous setbacks, which saw the cost rise from around £15bn to £19bn.
The new line is set to be crucial to London’s recovery from the pandemic, helping avoid a car-led recovery by providing new journey options, supporting regeneration across the capital, and adding an estimated £42bn to the UK economy.
Andy Byford, Transport for London’s Commissioner, said: “I am delighted that we can now announce a date for the opening of the Elizabeth line in May.
“We are using these final few weeks to continue to build up reliability on the railway and get the Elizabeth line ready to welcome customers. The opening day is set to be a truly historic moment for the capital and the UK, and we look forward to showcasing a simply stunning addition to our network.”
Direct services from Reading, Heathrow and Shenfield are expected to connect with the central section in autumn 2022, with full end to end services commencing no later than May 2023.
The opening of the Elizabeth line has always been planned to take place in stages to ensure the new section stations, signalling and infrastructure can run safely and reliably before it fully links in with services out to the east and west.