Troian Avery Bellisario (born October 28, 1985) is an American actress who guest-starred in NCIS as Sarah McGee.
She is the daughter of Donald P. Bellisario, the creator of both JAG and NCIS as well as the stepsister of Sean Murray who plays NCIS Special Agent Timothy McGee on "NCIS".
She also previously appeared in NCIS's parent series, "JAG", guest-starring in the JAG Season 3 episode, Tiger, Tiger (episode) as Erin Terry.
Bellisario is one of the stars of the television series "Pretty Little Liars", playing Spencer Hastings.
She is currently married to Patrick J. Adams who appeared in the NCIS Season 6 episode, Murder 2.0 (episode) with the two marrying on December 10, 2016 in Santa Barbara, California and they have two daughters.