She is known for her roles as Orla McCool in the Channel 4 sitcom Derry Girls (2018–2022) and the titular character of the Disney+ series Renegade Nell (2024).

Brought up in Dundrum, South Dublin,[1] Harland has two older sisters, Katie and Ellie.

[4] Upon graduation, Harland landed a recurring role as Kayleigh in season two of the RTÉ One series Love/Hate in 2011.

[6] In 2017,[7] 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.

[16] In March 2021, Harland performed with Sam Otto in an adaptation of the play Endless Second, by Theo Toksvig-Stewart, for BBC Radio 4.