In preseason ahead of the 2020–21 campaign, then-16-year-old Clinton was called up to train with the first team after manager Willie Kirk singled her out as "a really talented teenager, but she's probably our sixth-choice midfielder.

[4][5] She made her competitive senior debut for the club on 3 October 2020, appearing as a 74th-minute substitute for Izzy Christiansen in a 6–0 FA WSL victory over Aston Villa.

[6] On 1 November 2020, Clinton was named as part of the squad for the delayed 2020 Women's FA Cup Final at Wembley Stadium, where she was an unused substitute as Everton lost to Manchester City 3–1 in extra-time.

[11] On 14 January 2023, having not yet made an appearance for Manchester United, Clinton joined Women's Championship side Bristol City on loan for the remainder of the season.

[16][3] In total, Clinton scored six goals in 15 appearances in all competitions for Bristol City,[17] with her loan spell described as a "good stepping stone" by Skinner.

[21] On 21 January 2024, Clinton scored two goals and provided an assist in a 4–3 league win against West Ham, described as the main reason Spurs were the dominant side in the match.

[24] After two loan spells away from the club, Clinton made her Manchester United debut on 21 September 2024, starting and scoring in an opening day 3–0 win at Old Trafford.

[25] On 9 January 2024, having scored 4 goals in 10 appearances during the 2024–25 season, United triggered Clinton's one-year contract extension,[26] keeping her at the club until the summer of 2026.

[43] Clinton is also known to attentively defend when necessary, using her physicality and strength,[45] having previously been described as a "bit lazy out of possession" by her former manager at Everton Willie Kirk.