She is best known for her roles as Kaitlin Cooper in the Fox teen drama The O.C., Aqua in Kingdom Hearts, and Thea Queen in The CW series Arrow as well as its spin-off The Flash.

"[5][6][7] Upon returning to Los Angeles that September, Holland signed with Ford Modeling Agency at age seven,[7][8] and immediately booked a shoot for Burberry.

She was even slated to co-star in the 2005 Fox series The Inside with fellow model Rachel Nichols, but left the show when writer Tim Minear was brought in to overhaul it.

[9] In December 2007, Holland was cast in the independent drama film Garden Party, playing the role of April, a troubled teenage aspiring model who tries to make it in Los Angeles.

In May 2010, Square Enix announced she would be voicing Aqua in the PlayStation Portable title, Kingdom Hearts Birth by Sleep, which was released on September 7, 2010, in North America.