Ladislav John "Walter" Ostanek, CM[1][2] (born 20 April 1935) is a Canadian musician.

[5] After several years, Ostanek became a popular entertainer in Southern Ontario, performing Slovenian-style (also known as Cleveland-style) polkas and waltzes.

He has appeared in concert with Roy Clark, The Oak Ridge Boys, Ronnie Milsap, Ray Price, Mel Tillis, Brenda Lee, Slim Whitman, Tom T. Hall, T. G. Sheppard, Tommy Hunter, Lawrence Welk, Myron Floren, Frank Yankovic, Black Forest Band, and Weiss Blau.

Ostanek is also cited as the inspiration for the Second City Television polka parody, the Shmenge Brothers,[8] and the Osler show.

In July 2016 Ostanek was in the news when he won a million dollars in the London Dream Lottery, which raises money for hospitals.