Officials confirmed the event to the Calgary Sun on Friday. A main event has not yet been announced.
The UFC Fight Night, which will take place at Scotiabank Saddledome, will mark UFC's second trip to Calgary. The first live event there was UFC 149 in July 2012. It's remembered as one of the most cursed cards in UFC history, with multiple high-profile fights falling through because of injuries.
In what's become something of a running joke, UFC president Dana White has repeatedly stated over the years he "owes" Calgary an event.
Aldo (26-4) was supposed to fight in Calgary in 2012 but was one of the names to withdraw from the card. The 31-year-old Brazilian is considered the greatest featherweight of all time but has lost three of his past four bouts.
He is coming off back-to-back TKO losses to current champion Max Holloway.
Stephens (28-14) is riding a three-fight win streak. He knocked out Josh Emmett in a UFC Fight Night main event in February.