The ex-Middlesex opening batsman has replaced Paul Downton on the county's board after the latter resigned to concentrate on his new role as managing director of England Cricket.
The 37-year-old Strauss retired in 2012 and had been mooted as a possible contender for a role within the England and Wales Cricket Board, after Hugh Morris resigned as managing director in August.
Instead Downton has taken that ECB role, and 100-Test stalwart Strauss has stepped into his county shoes at Middlesex.
"We are absolutely thrilled that Andrew has accepted our invitation to join the Middlesex executive board," said Middlesex chairman Ian Lovett.
"He is a Middlesex man through and through, with an outstanding reputation within the game.
"Finding the right man to replace Paul Downton was always going to prove a challenge; however in Andrew Strauss we've found the perfect solution.
"My thanks on behalf of all at Middlesex go to Andrew for offering his services to the executive board, which we have no doubt will prove invaluable as the club moves forward with his continued involvement."
- Board & Management Changes
- Paul Downton
- Andrew Strauss