Linda Edna Cardellini (born June 25, 1975) is an American actress and voice actor. She is known for her roles as Lindsay Weir on Freaks and Geeks, Samantha Taggart on ER, Velma Dinkley in the live-action Scooby-Doo feature films, Sylvia Rosen, a neighbor of Don Draper's, on the AMC drama series Mad Men, Meg Rayburn on the Netflix original series Bloodline, and Laura Barton in Avengers: Age of Ultron. She is also known for voicing roles in animated projects such as CJ in Regular Show, Wendy Corduroy in Gravity Falls, Cassie in Brokeback Mountain, and Megan in Sanjay and Craig.