When Willy Wonka sings Pure imagination is it actually Gene Wilder singing?

No, it was not actually Gene Wilder singing. The singing voice of Willy Wonka in the 1971 film "Willy Wonka & the Chocolate Factory" was provided by Bill Shirley, an American singer and actor. Gene Wilder, who portrayed Willy Wonka, was not a professional singer and did not perform the songs in the film.