The 23-year-old came through the youth ranks of AFC Wimbledon before breaking into the first team in 2017 at the age of 17. Over the next five seasons, Anthony would make 152 appearances for The Dons (118 in League One). While at Wimbledon, Hartigan went on loan to Newport County where he would spend the second half of the 2020-21 season. Newport would make the League Two Play-Off final at Wembley, which Hartigan would feature in. In 2018, Hartigan was named the LFE Apprentice of the Year award for League One at the EFL Awards ceremony in London. Hartigan would then move to Mansfield Town in 2022 and make 23 appearances for The Stags. He now joins The Bees on a season-long loan.