Maguire met Jennifer Meyer in 2003 while he was shooting the movie "Seabiscuit". They became engaged in April 2006. Their daughter Ruby Sweetheart Maguire was born on November 10, 2006. The couple married on September 3, 2007, in Kona, Hawaii. Their second child, a son, Otis Tobias Maguire was born on May 8, 2009. The couple divorced in 2020.