Named in honor of Thomas Jamison, a long-time member of Oakmont Country Club and the founder of Hannastown Golf Club, the Jamison Cup in an Inter-Club championship contested annually among teams from WPGA Member Clubs. Inter-Club competition and league play have been a central part of the WPGA's history since the early 20th century. The Diebold League is the oldest in the Association and consists of Fox Chapel Golf Club, Longue Vue Club, Oakmont Country Club and Pittsburgh Field Club.

Jamison Cup teams consist of the club winners of leagues throughout Western Pennsylvania as well as at-large teams. Clubs send five player teams to the finals. Each league champion is guaranteed a berth in the Jamison Cup Finals. WPGA Member Clubs not currently participating in an inter-club league are encouraged to enter the Jamison Cup as an at-large team.

The championship is 36-holes of stroke play, college format, with the best three scores of four counting in each round. All players on a team must be members of the club for whom they are competing. Teams may use multiple players over the two rounds of competition, playing as many as 8 players (4 per round) per team.

Over the last few years the Jamison Cup has been played at Bedford Springs Resort and is the final West Penn Golf Association Championship of the season.