Johnny began his training in Sault Ste. Marie, ON at age 12. He graduated from Interlochen Arts Academy receiving the young artists’ award in dance. He has attended summer programs at the San Francisco Conservatory, Bartholin International Ballet Seminar and Hubbard Street. He has worked with Gleich Dances under the direction of Julia Gleich and was awarded 1st place at the 2010 American Ballet Competition in both the classical and contemporary divisions. He has performed roles in ballets such as Arthur Saint-Léon’s Coppelia, August Bournonville's La Sylphide and Frederick Ashton's Les Patineurs; as well as works by Randy Duncan, Patrick Corbin, Kim Robards and Hannah Baumgarten. McMillan joined Hubbard Street 2 as an apprentice in September 2010, became a company member in August 2011, and then joined the main company in May 2012.