Brittany Leanna Robertson was born in Charlotte, North Carolina, to Beverly (Hayes) and Ryan Robertson, a restaurateur. She was raised in South Carolina, the oldest of seven children. Her mother's worries about the public school system led to Robertson being home-schooled. She began acting at the Greenville Little Theater in South Carolina, and in her early teens moved to Los Angeles with her grandmother to seek TV and film opportunities. She won roles in various TV projects including Growing Pains: Return of the Seavers (2004). Success continued with appearances in Dan in Real Life (2007), Scream 4 (2011), and the lead roles in two series, Lux in Life Unexpected (2010) and Cassie in The Secret Circle (2011). Britt also starred in the television film Avalon High (2010), opposite Gregg Sulkin, had a supporting role in the Vince Vaughn film Delivery Man (2013), headlined the Nicholas Sparks book adaptation The Longest Ride (2015), opposite Scott Eastwood, and will star with George Clooney in the Brad Bird-directed science fiction adventure Tomorrowland (2015).