The 29-year-old midfielder signed a two-year pre-contract agreement with the Perth club in January.
But he later changed his mind and citied "family reasons" as he declared he wanted to remain in Dingwall with County.
A bitter dispute followed and the player was photographed training with the Staggies when he should have been reporting for duty with Saints for the first time.
Now St Johnstone say they have struck a satisfactory deal that will see the player remain in the Highlands.
A club statement read: "Following a meeting between our chairman Steve Brown and his opposite number at Ross County, St Johnstone FC wishes to announce that an agreement has been reached, on terms that are acceptable to St Johnstone, for the cancellation of the Scottish Premier League contract between St Johnstone FC and the player Richard Brittain."
- Sports & Recreation
- St Johnstone