Neil Patrick Harris is joining the circus.

Page Six is exclusively told that the “How I Met Your Mother” star will be the celebrity ringmaster for the grand opening of New York’s world famous “Big Apple Circus” on Sunday.

It’s the circus’ 42nd season, and its theme this year is “extraordinary New Yorkers.”

However, Harris is not the only celebrity taking part — the show also features the performing “Savitsky Cats” from “America’s Got Talent.”