Taylor makes the move to the Madejski Stadium just three days before Reading’s Sky Bet Championship opener at Birmingham.
“I’m delighted that we were able to get Andrew Taylor to join our squad for this season,” Royals boss Steve Clarke told the club’s website.
“He brings good experience and different attributes to our left back position.
“This was an area in the squad where we needed to make an addition and I feel we have made a good signing in Andrew.”
Taylor, who signed for Wigan from Cardiff on a three-year deal last June, made 27 appearances for the Latics during the 2014-15 season.