Comic book artists, TV actors, sports stars and video game studios will take part in the convention, which is being held throughout the day at Manchester Central.
Life's Too Short star Warwick Davis headlines the list of TV celebrities in attendance. Tom Hopper and Rupert Young from hit show Merlin, and the cast and crew from BBC series Young Dracula will also make an appearance.
Artists including Lee Bradley, Antony Johnston and John McCrea will showcase their work at the event's Comic Village, where budding illustrators will also have the chance to show off their portfolios.
Sports stars will also be there in full force, with ex-England goalie Peter Shilton and Manchester City greats Mike Summerbee, Tony Book and Colin Bell on the bill.
Gaming studio THQ is previewing Darksiders 2 at the event, Namco Bandai is showcasing Tales of Graces F, and Nintendo is offering hands-on opportunities with its 3DS XL.
The MCM Expo also has a strong manga, anime and cosplay focus, with anime voice artist Vic Mignogna on hand to meet fans and a Cosplay Masquerade taking place during the convention.
Tickets for the MCM Expo Manchester Comic Con are available to purchase until 7pm tonight (July 19) via the event's website.