In 2005, Huff co-founded the non-profit Kamay at Puso (which means "Hand and Heart" in Tagalog).
Her career began in 2006 with a role in the television series CSI: NY. She has made guest appearances in several television series, including roles in NCIS, Bones, Days of Our Lives, Chuck, Greek and The Suite Life on Deck.
In 2008, she was cast to star in the film Strawberry Cliff, opposite Hong Kong singer Eason Chan. In 2009, she starred in Disney Channel first original web series, Mackenzie Falls, a stand-alone spin-off of Sonny with a Chance. In 2011, she was cast in the film Cowgirls n' Angels, starring James Cromwell, Bailee Madison, Jackson Rathbone, Dora Madison Burge, and Kathleen Rose Perkins.
In 2013, she was cast in Cowgirls 'n Angels: Dakota's Summer, the sequel to Cowgirls 'n Angels opposite Keith Carradine, Haley Ramm, Emily Bett Rickards, and Jade Pettyjohn. In 2016, Leslie became a recurring character on the seventh season of the American supernatural television series, The Vampire Diaries, as a vampire huntress named, Rayna Cruz.
