Seehorn was born in Norfolk, Virginia, although she also grew up in Japan, Arizona and Washington, D.C. She studied painting, drawing, and architecture from a young age, following in the footsteps of her father and grandmother. She continued in the visual arts, but had a growing passion for film and theater and was introduced to contemporary theater in college. Seehorn graduated from George Mason University in 1994 with a Bachelor of Arts in Art Studio.