Peter Sarsgaard has Danish (from a great-grandfather), Norwegian (from a great-grandmother), English, German, Irish, Scots-Irish/Northern Irish, and Austrian, ancestry.
Peter Sarsgaard was born on March 7, 1971, in St. Clair County, Illinois, the United States, to Judy Lea (née Reinhardt) and John Dale Sarsgaard. His father was an Air Force Engineer and thus the family moved a lot during Sarsgaard’s childhood.
As a child, he watched soccer on TV all the time and aspired to become a soccer player. He also took ballet classes when he heard that some soccer players learned ballet to improve their coordination; however, he gave up soccer when he suffered many concussions while playing, and became interested in writing and theater.
His surname originates in Denmark, where his paternal great-great-grandparents were born.