The American Pie star and Thyfault, a travel agent, tied the knot on Sunday at the Rainbow Ranch in Montana, according to Us Weekly. About 115 guests attended the ceremony.
The couple announced their engagement in December after three years of dating. This is the first marriage for Klein, 36, who was previously engaged to Katie Holmes until they called it off in 2005.
Next up for Klein professionally is the World War I drama Out of the Burning Blue, which is scheduled to be released later this year.