The ambitious plans will start within weeks of its pubs reopening fully as lockdowns ease.
It has a pipeline of 75 projects – 18 of which are new pubs and 57 “significant extensions and upgrades” to its existing 871 pubs.
The first new pubs and extensions will be in towns and cities including Glasgow, Leeds, Birmingham, Sheffield, Felixstowe and Haverfordwest.
Once all 75 projects in the pipeline are completed, the group said it anticipates investing £750m to open 15 new pubs and enlarging 50 existing sites each year for ten years, creating as many as 20,000 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.”
Earlier this month, the pub chain said it will be able to welcome customers back inside their premises in Scotland from April 26, though strict new rules mean alcohol can only be consumed outdoors, until 10pm.
Customers, however, will be able to enjoy a meal indoors with non-alcoholic drinks.