Isabel LeBourdais, née Erichsen-Brown (15 April 1909 – 2003) was a Canadian journalist and author. She is best known as the author of the 1966 book The Trial of Steven Truscott, the first major work to argue that Steven Truscott had been wrongfully convicted of murder.
Educated at Havergal College and the University of Toronto, she left university in 1929 to marry Stephen Dale, whom she divorced four years later. She subsequently became a social activist, and joined the Co-operative Commonwealth Federation. She married writer and CCF politician Don LeBourdais in 1942. She continued working as a journalist and activist until publishing the Truscott book. Thereafter, she became a public relations officer for the Registered Nurses Association of Ontario.
She was the sister of novelist Gwethalyn Graham and the grandmother of musician Mark LeBourdais, formerly of King Apparatus.