KATIE Holmes channeled her inner Judy Garland last night on “So You Think You Can Dance” — singing and hoofing to Garland’s trademark tune, “Get Happy.”

Holmes, making a rare TV appearance, helped “SYTYCD” celebrate its 100th episode with her spunky routine, choreographed by Emmy-nominated Tyce Diorio.

PHOTOS: Katie Holmes Takes ‘SYTYCD’ Stage

No stranger to TV, thanks to her breakthrough role on “Dawson’s Creek,” Holmes — now also known as Mrs. Tom Cruise — sashayed on stage looking very Garland-esque with her black hat, black jacket and black short-shorts.

In addition to her number, Holmes appeared on “SYTYCD” to promote the Dizzy Feet Foundation, of which she’s a founding member along with “SYTYCD” host/executive producer Nigel Lythgoe, director Adam Shankman and “Dancing With the Stars” judge Carrie Ann Inaba.

The foundation’s goal is to support, improve and increase access to dance education in the US through scholarships and educational programs.

Watch Holmes’ performance below.