Sky Blue FC McCaskill was selected by the
Boston Breakers as the number two overall pick at the
2018 NWSL College Draft. After the team folded due to failed buyout negotiations in late January, McCaskill was selected by
Sky Blue FC with the second pick in the
2018 NWSL Dispersal Draft. She scored her first career goal on April 21 against the
Chicago Red Stars. McCaskill was a finalist for 2018
NWSL Rookie of the Year, alongside
Andi Sullivan and
Imani Dorsey.
Loan to Sydney FC McCaskill signed with
Sydney FC for the
2018-19 W-League season, joining fellow Americans
Sofia Huerta,
Danielle Colaprico and
Aubrey Bledsoe in Sydney. She scored her first goal for Sydney FC in a 5–2 win over Adelaide United in December 2018, before scoring a brace the following month against Newcastle Jets in a 3–1 win. Sydney FC advanced to the
2019 W-League Grand Final, Sydney won 4–2. McCaskill scored two goals and recorded an assist. She was named Player of the Match award for her performance.
Chicago Red Stars On June 19, 2019, McCaskill was traded to the
Chicago Red Stars in exchange for a first and second round draft pick at the
2020 NWSL College Draft. McCaskill made her Red Stars debut on June 23, 2019, in a game where the Red Stars played
Reign FC. McCaskill scored her first goal for the Red Stars in a 3–0 win over the
Houston Dash.
Racing Louisville Before the
2021 Season Chicago traded McCaskill as well as
Yuki Nagasato's rights to
Racing Louisville FC as well as a 2021 International Roster spot and the No. 5 overall pick in the
2021 NWSL Draft. McCaskill made her debut for Louisville on April 10, 2021, in their first game. She scored her first goal against her former team,
Chicago Red Stars in a 3–0 win.
Angel City FC After the
2021 Season McCaskill was traded to
Angel City FC in exchange for the No. 6 pick in the
2022 NWSL Draft and $25,000 in allocation money. Louisville later traded that pick to
North Carolina Courage for
Jessica McDonald. McCaskill was Angel City's joint top scorer with
Alyssa Thompson with four goals in the 2023 regular season. On July 29, she scored two goals in a 2–1 win against the
Portland Thorns in the
Challenge Cup group stage. She assisted Thompson and scored the stoppage-time winner in a 2–1 win against the
Houston Dash on October 8. She was named
NWSL Player of the Month two times and selected to the
NWSL Second XI at the end of the year. She left Angel City with 11 goals and 5 assists in 44 regular-season games.
San Diego Wave With the completion of the
2023 NWSL season, McCaskill became a free agent. On December 20, 2023,
San Diego Wave FC announced the signing of McCaskill to a three-year contract. She made her debut with the Wave on March 15, 2024, in an
NWSL Challenge Cup game against
NJ/NY Gotham FC. McCaskill assisted
Alex Morgan on the game-winning goal, serving up a corner kick in the 88th minute of the match. On the last game of the Wave's 2024 season, McCaskill scored her first goal with the club in a 3–1 win against
Racing Louisville FC. In her second year at San Diego, McCaskill found herself playing in a deeper role alongside new acquisition
Kenza Dali. She helped the Wave reach a sixth-place finish in the league and qualify for the playoffs for the third time in club history. However, due to an injury, McCaskill was not able to play at the tail end of the season and watched on from the sidelines as the Wave were beaten in the quarterfinals by the
Portland Thorns. She had appeared in 21 matches (starting all but one) up to that point.
Gotham FC On January 2, 2026, it was announced that McCaskill had been traded from San Diego to
Gotham FC in exchange for $175,000 in intraleague transfer funds; she had previously played for Gotham in the
Sky Blue FC era from 2018 to 2019. On February 1, 2026, she scored once to help Gotham win the
FIFA Women's Champions Cup third place match over
AS FAR, her first goal in her second stint with the club. ==International career==