The Tacoma Defiance, formerly Seattle Sounders FC 2, are an American professional soccer team based in the Puget Sound region in Tukwila, Washington, United States.

S2's home matches were to be played at the MLS team's training facility, the Starfire Sports Complex in Tukwila, beginning in the 2015 season.

[10] The Rainiers partnered with the Tacoma Stars, an indoor soccer team, and discussed a potential move for S2 with the Sounders organization.

[11][12] The Sounders had previously discussed plans to move their lower-league franchise to the Tacoma area in the 2000s in the event of a successful MLS expansion bid.

[19] MultiCare Health System was named as the team's jersey sponsor and Reign FC of the National Women's Soccer League also announced a move to Cheney Stadium for the 2019 season.

[20] Sounders FC Academy Director Chris Little had been named as the team's new head coach a week earlier, replacing John Hutchinson.

[22] As a result of Minor League Baseball rules rendering Cheney unavailable,[23] and the abandonment of the Tacoma soccer stadium project,[24] the Defiance relocated back to Starfire.

The club's crest is a black circle featuring an image of a stylized ship, based on USS Point Defiance, in the foreground and the tentacles of a Giant Pacific octopus surrounding it.

[25] S2 initially played its home matches at Starfire Sports Complex's main stadium, which seats 3,500 spectators and is located in the suburb of Tukwila, Washington.

[29] For soccer matches, the pitch was aligned to the third base line, the pitcher's mound was removed, and the dirt infield was filled with grass.

[40] Andrew Opatkiewicz was hired as the General Manager in October 2014, having experience with Seattle Wolves FC (now Washington Crossfire).

[41] Prior to the start of the 2017 USL season, Schmid was formally named the S2 GM and John Hutchinson was added as an assistant coach on Hendrickson's staff.

[44] Webber left the position in November 2023 and was replaced two months later by Hervé Diese, a former assistant coach for CF Montreal and Angel City FC.