The ambitious plans will start within weeks of its pubs reopening fully as the lockdown eases.
A total of 18 new pubs will open and “significant extensions and upgrades” will be made to scores of current pubs.
The first new pubs and extensions will be in towns and cities including Leeds, Birmingham, Newport Pagnell in Buckinghamshire, Sheffield, Felixstowe in Suffolk, Heswall on the Wirral, Dublin, Haverfordwest in Pembrokeshire, Carmarthen and Glasgow.
Once all 75 projects in the pipeline are completed, Wetherspoon said it anticipates investing £750 million to open 15 new pubs and enlarging 50 existing pubs each year for 10 years, creating 20,000 new jobs.
Wetherspoon founder and chairman Tim Martin said: “Our immediate investment will provide work for architects, contractors and builders as well as result in 2,000 new jobs for staff in our pubs.
“We are geared up to start on the first projects within a few months.
“We are also committed to our long-term investment and job creation programme over the next decade.
“However, the investment is conditional on the UK opening back up again on a long-term basis, with no further lockdowns or the constant changing of rules.”