Jaimie Alexander, born Jaimie Lauren Tarbush on March 12, 1984, in Greenville, South Carolina, is an American actress best known for her roles as Jessi on the TV series "Kyle XY" and Lady Sif in the Marvel Cinematic Universe films "Thor," "Thor: The Dark World," and "Thor: Love and Thunder."

She moved to Grapevine, Texas, with her family when she was four years old and grew up as the only girl among five siblings. She first got into acting in grade school, where she took theater for fun, but she was kicked out of theater in high school because she could not sing. Instead, she focused on sports.

At the age of 17, she substituted for a friend at a meeting with a scouting agency, where she met her manager, Randy James, who sent her some scripts. After graduating from Colleyville Heritage High School, she moved to Los Angeles to pursue her acting career. 

Her career was launched in 2003 when she was cast in the leading role of Hanna Thompson in the low-budget, award-winning film "The Other Side." She was originally at the audition to help out by reading against the male actors, but the director decided to cast her in the leading role after hearing her perform the lines.

Her next role was in the movie "Squirrel Trap," where she played Sara, the love interest of the main character. She also had guest appearances on shows like "It's Always Sunny in Philadelphia" and "Standoff." She appeared in the series "Watch Over Me" and had lead roles in horror films such as "Rest Stop" and "Hallowed Ground."

In 2007, she began starring in the ABC Family television show "Kyle XY" as Jessi, a troubled show-off with superhuman powers.

Her biggest role came in 2011 when she was cast as Lady Sif, a warrior goddess of Asgard, in the Marvel film "Thor." She reprised her role in its sequels and appeared in the television series "Agents of S.H.I.E.L.D." and the Disney+ series "Loki." From 2015 to 2020, she starred in the NBC series "Blindspot" as Jane Doe, a woman with amnesia and mysterious tattoos.