[5] In 1961, Whitehead directed Doric Wilson's first play to be performed, And He Made a Her, a comedy that was an off-off-Broadway production at the Caffe Cino.

[13] During his tenure he was able to push through a plan of building the purpose-built 869-seat state-of-the-art Festival Theatre to expand considerably the capacity for audiences at Niagara-on-the-Lake.

[14] Queen Elizabeth II, Indira Gandhi, and Pierre Trudeau were among those who attended performances at the Shaw Festival Theatre during its inaugural season in 1973.

[12] His notable appearances included The Apple Cart, Major Barbara, The Philanderer, Arms and the Man, Misalliance, and Heartbreak House with Jessica Tandy.

[16] Whitehead and Suzanne Grossman adapted Georges Feydeau's plays There's One in Every Marriage for the Broadway stage in 1971 and Chemin de Fer in 1974.

[17] Whitehead received an honorary degree in arts from Trent University in 1978 and earned an Antoinette Perry "Tony" Award nomination for Camelot in 1980.

[22][23][24] Whitehead began previews of The Importance of Being Earnest by Oscar Wilde on Broadway at the American Airlines Theatre on 17 December 2010 in the role of Reverend Canon Chasuble.