The 51-year-old is in the town performing as Baron Hardup in the pantomime Cinderella.
Tweeting about being stopped by North Wales Police officers on Sunday night, he said: "Randomly stopped for breathalyser test, had a laugh, made some new friends! Safe, clean town, love it!"
Osmond passed the test - oh yes he did!
American singer Jimmy Osmond has posted a video of himself being breathalysed by police officers in Llandudno.