Mark Dailey was born in Youngstown, Ohio in 1953. He studied law enforcement at Youngstown University, and started out with a career as a police officer in Ohio. He would become a radio reporter in Ohio, and then moved to Detroit to work as a crime reporter. In the early 1970s, Dailey went to Windsor, Ontario, to work for CKLW. In 1974, Dailey joined the staff at CHUM in Toronto. Five years later, he took a job at CityTV, where he specialized in crime reporting. Dailey anchored the CityPulse and CityNews programs.

In the 1980s, Dailey began providing voiceovers for CityTV. He also recorded announcements for the programming of the day for the station's telephone system. Dailey provided voiceover introductions for CityTV's Late Great Movies segment, and would also go on to anchor the station's 11 p.m. newscast. In 2009, Dailey celebrated his 30th anniversary with CityTV.

Dailey provided his voice for the English dubs of two anime series. He was the voice of Brad Best in Beyblade, and he also voiced Eddie, Roks, and Rokusho for Medabots. Dailey's other credits include The Life Before This in 1999, The Ripping Friends in 2001 (as Crag), Childstar in 2004 (as a news anchor), and Toronto Stories in 2008 (as a newscaster).

In 2004, Dailey was diagnosed with prostate cancer, and he was able to beat the disease. He became an advocate for men's health; he ran a special series on prostate cancer, and advocated that men go for regular PSA testing. Dailey also became a board member with Prostate Cancer Canada.

It had been rumored that Dailey was the voice in the chorus of the Rush song "Subdivision"; however, he dispelled this myth in a 2009 posting on CityTV's website. When Dailey had time off, he would drive a tractor-trailer for a trucking company. He also played the trombone.

In September 2010, Dailey announced that he had been diagnosed with kidney cancer. He lamented publicly that kidney cancer was different from prostate cancer, because kidney cancer is much harder to detect until it was far advanced. Dailey cut back on his airtime to focus on treatments for his kidney cancer.

Sadly, Mark Dailey passed away at Sunnybrook Hospital in Toronto on Monday, December 6, 2010 at the age of 57, due to complications from kidney cancer. He is survived by his wife Kim, his stepdaughter Nicole, two sisters, and his parents.