They formerly competed in the Northwest Division of USL League Two.
Eastside FC was founded in 1970 as a youth soccer club.[2][3] In 2016, they became an affiliate club of Major League Soccer team Seattle Sounders FC.[4] After the 2019 USL League Two season, the Sounders decided to withdraw their U-23 team from the league, where they would be replaced by Eastside FC, who would use their own name and branding, rather than the Sound FC name.[5]