Linda Edna Cardellini is an American actress. 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, Cassie in Brokeback Mountain, and Laura Barton in Avengers: Age of Ultron. She is also known for voicing roles in animated projects such as CJ in Regular Show, Marcy "Hot Dog Water" Fleach in Scooby-Doo! Mystery Incorporated, Wendy Corduroy in Gravity Falls, and Megan in Sanjay and Craig.