| 2015 season | ||||
|---|---|---|---|---|
 | ||||
| General manager | Garth Lagerwey | |||
| Head coach | Sigi Schmid | |||
| Stadium | CenturyLink Field | |||
| Major League Soccer | Conference: 4th Overall: 6th | |||
| MLS Cup Playoffs | Conference Semifinals | |||
| U.S. Open Cup | Fourth round | |||
| CONCACAF Champions League (2015–16) | Quarterfinals | |||
| Cascadia Cup | Winners (4–2–0) | |||
| Heritage Cup | Runners-up (0–1–1) | |||
| Desert Diamond Cup | 4th (1–2–0) | |||
| Top goalscorer | League: Obafemi Martins (15)[1] All: Obafemi Martins (15) | |||
| Highest home attendance | 64,358 (Aug. 30 vs. Portland)[1] | |||
| Lowest home attendance | League: 39,175 (Mar. 14 vs. San Jose)[1] All: 37,106 (Aug. 19 vs. Olimpia, CCL) | |||
| Average home league attendance | Regular season: 44,245 Playoffs: 39,568 All: 39,877 | |||
| Biggest win | League: 4–0 vs. Orlando (Aug. 16)[1] | |||
| Biggest defeat | League: 1–4 at Portland (June 28)[1] | |||
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The 2015 Seattle Sounders FC season was the club's seventh season in Major League Soccer, the United States' top-tier of professional soccer. Including previous Seattle Sounders franchises, this was the 35th season of a soccer team playing in the Seattle metro area.