John Krasinski is the youngest of three sons. His father is Boston internist Dr. Ronald Krasinski and his mother is a nurse.
Krasinski graduated from Newton South High School in 1997 and from Brown University in 2002 as an honors playwright. His elder brother Paul also attended Newton South High School in 1994, and Brown University in 1998.
Krasinski's first stage experience was starring in a satirical high school play written and cast by B.J. Novak
, now a writer and co-star on The Office
. John Krasinski later studied one semester at the Eugene O'Neill National Theater Institute in Waterford, Connecticut.
Among Krasinski's television credits are appearances in NBC's Law & Order: Criminal Intent
, and a 2005 episode of CBS's CSI
. He is most recognized for his role as Jim Halpert on NBC's The Office