She is best known for several roles, including Gretchen Witter, the sister of Pacey Witter on Dawson's Creek, as Lucy in Yes Man (2008); and as Catherine in He's Just Not That Into You (2009). Most viewers would recognize Alexander as former Secret Service/NCIS Special Agent Kate Todd, a role that Alexander played in the first two seasons of NCIS.
She currently stars as Chief Medical Examiner Maura Isles on the Turner Network Television series Rizzoli & Isles.
Sasha Alexander was born Suzana S. Drobnjaković in Los Angeles, California, to Serbian parents. She began acting in school productions in the seventh grade. She also was an ice skater but had to stop due to a knee injury. She continued acting through high school and college, and then moved to New York to act in summer stock and Shakespeare festivals. She graduated from the University of Southern California's School of Cinema-Television, where she was a member of the sorority Kappa Alpha Theta, before going on to have a successful acting career in both TV and film.
Alexander got her start as a Fly Girl on In Living Color, then became a regular on two short-lived series: the medical drama Presidio Med and ABC's twenty-something drama Wasteland. She achieved widespread media attention and critical praise when she appeared on the fourth season of Dawson's Creek as Gretchen Witter, dating the title character, and in an episode of the short-lived Fox comedy series Greg the Bunny, in which she played the part of a lesbian TV Guide reporter and shared an onscreen kiss with Sarah Silverman. Alexander has also appeared in the films Lucky 13, and All Over the Guy as well as He's Just Not That Into You, the independent movie The Last Lullaby, and Yes Man starring Jim Carrey.
Before being cast as Caitlin Todd on NCIS, she appeared on CSI as District Attorney Robin Childs, in the episode "Alter Boys".
Alexander joined NCIS as Secret Service/NCIS Special Agent Caitlin "Kate" Todd in 2003. She replaced Vivian Blackadder played by Robyn Lively, who only appeared in the back-door pilot episodes, "Ice Queen" and "Meltdown" on JAG. The official pilot episode "Yankee White" aired September 23, 2003 on CBS.
Alexander's year and a half tenure on the show ended in May 2005 when her character, Kate, was killed off when a terrorist shot her in the head in the last few seconds of the Season 2 finale, "Twilight".
In her final two appearances in both "Kill Ari (Part I)" and "Kill Ari (Part II)", Alexander was credited as a Special Guest Star. Chilean actress Cote de Pablo, who plays Ziva David, later permanently replaced Alexander on the show. However, despite having left the show, Alexander made a few further appearances in NCIS with her last one being on the 200th episode, "Life Before His Eyes". However, she wasn't given any official credit of any kind for those appearances, making her appearances in Seasons 1 and 2 as well as her guest appearances in the first two episodes of Season 3 the only ones where she has been credited.
She also had a small role in 2006's Mission Impossible III. She joined the cast of The Nine in the role of Nick's ex-wife. She also appeared in one episode of Friends ("The One with Joey's Interview"), playing a Soap Opera Digest reporter who interviewed Joey.
Her current television role is that of Boston medical examiner Maura Isles on the TNT series Rizzoli & Isles, which debuted on July 12, 2010.
On August 11, 2007, Alexander married director Edoardo Ponti, son of actress Sophia Loren and the late film producer Carlo Ponti, in Geneva, Switzerland. Alexander and Ponti have two children, Lucia Sofia (born May 12, 2006) and Leonardo Fortunato (born December 20, 2010).
Sasha Alexander at the Internet Movie Database