Janney has never been married and has no children, of which she said: "I’ve never had that instinct to have kids, I’m at peace with it". She was romantically involved with computer programmer Dennis Gagomiros. The couple began dating in 1994, and were interested in getting married but ended their relationship after seven years together in 2001. In 2002, she met actor Richard Jenik (her co-star in "Our Very Own"). The couple got engaged in 2004 but broke up two years later in 2006. In 2012, Janney met production manager Philip Joncas. The two met on the set of "The Way, Way Back" and began dating soon after. The couple dated for five years before ending their relationship in 2017.