Toronto Lady Lynx In 2012, Lacasse played with the
Toronto Lady Lynx in the
USL W-League.
ÍBV After receiving offers to play for teams in the United States and Europe, Lacasse signed with Icelandic club
ÍBV in the
Úrvalsdeild kvenna in 2015. In 2016, she won the
League Cup and in 2017, she won the
Icelandic Cup with ÍBV. In 2018, the team were runner-ups in the
Super Cup and she was named ÍBV's Player of the Year, and was she was named the league's best player by the newspaper
Morgunblaðið.
Benfica After being spotted by a Portuguese agent while playing in Iceland, Lacasse signed a two-year contract in July 2019 with Portuguese club
Benfica in the
Campeonato Nacional Feminino. On November 17, 2021, she became the first player to score a goal for a Portuguese club in the group stage of the
UEFA Women's Champions League after scoring the opening goal in a 2–1 victory over
BK Häcken FF. In 2021, she extended her contract until 2024. With Benfica, she is a three-time
Campeonato Nacional Feminino winner (2020–21, 2021–22, 2022–23), a three-time
Taça da Liga winner (2020, 2021, 2022), and a two-time
Supertaça de Portugal winner (2019, 2022). In her final season with the club, she scored 35 goals and added 18 assists in 43 games across all competitions. Over her four seasons, she scored over 100 goals and won eight trophies.
Arsenal On June 29, 2023, Lacasse signed with
Women's Super League club
Arsenal. She called the move a "dream", citing a desire to be part of a team with strong internal competition for playing time. On October 6, 2023, Lacasse came on as a substitute in an away match against
Manchester United, scoring her first Arsenal goal in second-half stoppage time to help salvage a point in a 2–2 draw. Lacasse scored a goal in the 3–1 victory against Manchester United in front of the first sold-out crowd for a
Super League match at
Emirates Stadium. She ultimately made 28 appearances for Arsenal across all competitions and won the
Women's League Cup with Arsenal, but only started in six of nineteen games in the WSL.
Utah Royals in 2025 In August 2024, Lacasse transferred to the
Utah Royals of the
National Women's Soccer League. In late October 2024, Lacasse ruptured her ACL and sprained her MCL, which would force her to miss the remainder of the season. After spending ten months recovering from her injury, Lacasse returned to the field on August 8, 2025, in a loss to the
Kansas City Current. ==International career==