Louisa Clare Harland (born January 31, 1993) is an Irish actress best known for her role as Orla McCool in the Channel 4 sitcom Derry Girls and the titular character of the Disney+ series Renegade Nell.

Brought up in Dundrum, South Dublin, Harland has two older sisters, Katie and Ellie. She was part of the Ann Kavanagh Youth Theatre in Rathfarnham. She trained at the Mountview Academy of Theatre Arts in London.

Upon graduation, Harland landed a recurring role as Kayleigh in season two of the RTÉ One series Love/Hate in 2011. She later appeared in films Rob Burke's Standby (2014) and Woody Harrelson's Lost in London (2017).

In 2017, it was announced Harland had been cast as Orla McCool, the eccentric cousin of Erin Quinn (Saoirse-Monica Jackson), in the Channel 4 sitcom Derry Girls. The first series aired in January 2018, receiving critical and commercial acclaim, and the second in March 2019. A final third series, as well as a special, aired in 2022.