The Seattle Mariners farm system consists of six Minor League Baseball affiliates across the United States and in the Dominican Republic. Three teams are independently owned, while three others—the Modesto Nuts, Arizona Complex League Mariners, and Dominican Summer League Mariners—are owned by the major league club.
The Mariners have been affiliated with the Triple-A Tacoma Rainiers of the Pacific Coast League and High-A Everett AquaSox of the Northwest League since 1995, making them the longest-running affiliations in the organization among teams not owned by the Mariners. Their newest affiliates are the Double-A Arkansas Travelers of the Texas League and the Single-A Modesto Nuts of the California League, which became Mariners affiliates in 2017.
Geographically, Seattle's closest domestic affiliate is the Tacoma Rainiers, which are approximately 26 miles (42 km) away. Seattle's furthest domestic affiliate is the Arkansas Travelers some 1,781 miles (2,866 km) away.