Melissa Gilbert arriving at a dance studio in Hollywood, California, March 14, 2012. (WENN.COM)

Actress Melissa Gilbert is set to marry The West Wing star Timothy Busfield.

The couple became engaged over the Christmas break and celebrated its impending nuptials during a lavish party at Los Angeles eatery Mr. Chow on Monday, a representative confirmed to UsMagazine.com.

A source says, "They got engaged over the holidays. They've known each other for quite some time, as their paths have crossed off-and-on over the past 20 years."

It will be the third marriage for both TV veterans - the former Little House on the Prairie star and mother-of-two's exes include actor Bo Brinkman and Bruce Boxleitner, who she divorced in 2011. Busfield, who has three children of his own, was previously wed to Radha Delmarter and Jenny Meriwin.