The Office star — whose character, Pam Beesly, is currently engaged on the hit NBC show — will wed writer Lee Kirk, her rep confirms to Usmagazine.com.
The couple were engaged on June 30 while on vacation in Europe.
Fischer and Lee, 37, have been dating since January 2008.
The actress, 35, was previously married to director James Gunn for nearly seven years before they divorced in July 2007. This is the first marriage for Lee.