Fire crews from Shrewsbury, Wellington and Whitchurch stations were called to Grindley Brook Locks at about 9am.
A spokeswoman for the service said: "It was a narrowboat or barge that had got stuck in the bottom of a lock and that had been empty.
"It was 10 feet down and the people on the boat were elderly so they couldn't climb the ladder to get out.
"There was a problem with the lock so they couldn't fill it up again with water either."
A nine-metre ladder was used to rescue the pair from the lock. Once they were out, crews attempted to fill it back up, but water was going into the boat.
A specialist team from the Shropshire Union Canal was called to sort the lock and refill it safely.
West Midlands Ambulance Service was also at the incident, but no-one was injured and no-one was taken to hospital.
The two were rescued by 9.30am when fire crews left the site.