Derby debut for Dunshaughlin jockey
Mangan is now based with British trainer John Jenkins and will ride 1,000/1 outsider Diore Lia in the Investec Derby at Epsom on Saturday.
Mangan began her career with Curragh trainer Frank Ennis in 2008 and she partnered her first winner in 2009 when she rode the Ennis-trained Salazar to victory at Roscommon.
Her last outing in Ireland was at Dundalk in October in 2011 and she has been riding in Britain since, she was in action at Yarmouth last Wednesday.
The British Horseracing Authority (BHA) has confirmed that there are no rules which preclude an apprentice from partnering the rank outsider Diore Lia in Saturday's Investec Derby.
Diore Lia will run in the Epsom showpiece with the Meath woman on board for owner Richard Aylward who is keen to generate maximum publicity for Great Ormond Street Children's Hospital by running his homebred filly in the big race.
Diore Lia finished unplaced in two maiden starts for trainer Jane Chapple-Hyam, the most recent on Friday 12th May in a Class 5 maiden at
Lingfield, but has now switched to trainer John Jenkins, who is Mangan's boss.
The last apprentice to ride in the Derby was Mark Coumbe, who partnered Castlemorris King in the 2011 race that was won by Pour Moi for trainer
Andre Fabre.