Ian Cassidy was born in Marin County, California, and received his training there from David Roxandy and Jody White at Dance Theater Seven. He joined Houston Ballet in 1998 after studying at Houston Ballet's Ben Stevenson Academy and was promoted to soloist in 2002.

Mr. Cassidy’s principal roles include the Prince in The Nutcracker and Marc Antony in Ben Stevenson’s Cleopatra. He has been featured in the full-length ballets Giselle, Swan Lake, The Snow Maiden and Peter Pan, as well as Stanton Welch’s Indigo and Bruiser; Dominic Walsh’s The Illusion of Separation and Dolcemente; Ben Stevenson’s Five Poems and Dusk; Nacho Duato’s Without Words; Trey McIntyre’s Second Before the Ground; and Natalie Weir’s Steppenwolf.

Mr. Casady was promoted to principal dancer in March 2007.