The 30-year-old arrived at Kingsholm in 2008 from Sale Sharks and has gone on to make 84 appearances for the Cherry and Whites.
However with Darren Dawidiuk establishing himself as Gloucester's first-choice No.2 this season, the club have agreed to let Lawson leave at the end of the current campaign.
Head coach Bryan Redpath said: "Scott's always given nothing less than his best for Gloucester during his time with us.
"He'll go with our best wishes and we wish him well for the future."
Sale and Wasps had been monitoring Lawson's future, while the Scottish Rugby Union are keen for the former Glasgow front-rower to return north of the border.