Union Omaha

In 2019, USL1 awarded a franchise to Alliance Omaha Soccer Holdings to begin play in the 2020 season. The decision to bring the league to Omaha, Nebraska, came as part of the USL's initiative to bring teams to communities without professional soccer.

An addition more than two years in the making finally became a reality in October 2019, when Alliance Omaha Soccer unveiled the team's name, colors and crest design.

Prior to its inaugural season, Union Omaha named former University of Nebraska Omaha head soccer coach Jay Mims the club's first manager. Mims took the Owls to the playoffs in all three of his seasons at the helm and managed to get the club to the League One Finals in both 2020 and 2021. He remained in charge until his resignation on Dec. 16, 2022.

Union Omaha finished the 2020 season in second place and qualified for the USL1 championship game. However, the match was canceled due to an outbreak of COVID-19 within the team's roster.

By defeating the Richmond Kickers 2–0 in the second to last match of the 2021 season, the Owls became the USL League One regular-season champions and clinched the top seed for the playoffs. Union Omaha then finished the season winning their first ever championship, beating defending champion Greenville Triumph SC 3–0 in the final.

Union Omaha made a deep run in the 2022 U.S. Open Cup, entering in the second round and advancing to the quarterfinals as the last remaining third division team in the competition. In April, the Owls defeated Major League Soccer club Chicago Fire FC in a penalty shootout in the third round, becoming the first USL1 team to defeat an MLS team in U.S. Open Cup history. After defeating fellow USL1 side Northern Colorado Hailstorm FC, Omaha played Minnesota United FC of MLS in the Round of 16 and won 2–1. They were the first third division team since Orlando City in 2013 to advance to the U.S. Open Cup quarterfinals. The club's run in the competition ended with a 6–0 defeat to hosts Sporting Kansas City in the quarterfinals; approximately 700 fans traveled from Omaha to attend the match at Children's Mercy Park in Kansas City, Kansas.

After slipping to fifth in the standings and losing in the quarterfinals in 2022, Mims stepped down and the club announced the hiring of Dominic Casciato to take his place. In his first season in charge, Casciato led Union Omaha to 14 consecutive wins to finish the season. The Owls eventually lost in the semifinals of the playoffs, but their 14 straight wins helped them earn the USL League One Players' Shield given out to the team sitting atop the league standings at the end of the regular season.

On Jan. 25, 2024, the club announced their plans to build a dedicated soccer stadium in Downtown Omaha.

Then, on Nov. 17, 2024, Union Omaha won its second USL League One title, defeating expansion team Spokane Velocity FC 3–0. In front of the largest crowd in USL League One Finals history, the Owls became the first USL League One club to win a second championship. Union Omaha also won their third USL League One Players' Shield in 2024.