And he's not the first Canadian politician who has faced a battle with the disease, nor is he the first to fight it while in office.
In 2010, NDP Leader Jack Layton announced that he was fighting prostate cancer, but he nevertheless carried on campaigning and led his party to become official opposition in the House of Commons. He died in 2011.
At the time of his passing, Ford was visibly distraught as they had sat on city council together.
Ford assisted in planning a memorial for Layton. Layton's widow Olivia Chow is now supporting Ford, saying that she will not engage now-mayoral rival Doug Ford while he deals with his brother's illness. On Wednesday, Chow also mentioned her own battle with cancer in 2005.
Here is a look at Canadian politicians who have fought cancer: