Mark Foster, who notched up six world swimming titles, ten European titles and two Commonwealth titles, officially opened the Station Road facility following a £1.2million refurbishment.
He was joined by the Mayor of Taunton Deane, Cllr Dave Durdan, and other dignitaries for a ribbon cutting ceremony.
The Olympian then swam against winners of a competition organised by Tone Leisure.
Mark said: "This pool’s a fantastic resource that the council and Tone Leisure have created for the people of Taunton and surrounding areas, and who knows? It may even produce an Olympic swimmer."
Work has included stripping out the building, making the reception area more welcoming, converting the changing rooms into a shared ‘village’ and replacing old plant equipment to improve air quality.
The revamp was funded by Taunton Deane Council, aided by a £500,000 Sport England grant.
The pool closed in October and re-opened on May 23, before yesterday's official ceremony.