Fire crews from Morecambe and Lancaster were called to the blaze on Morecambe Street West at approximately 3:40am this morning.
The fire had broken out on the ground floor of the property and three casualties were taken to hospital to be treated for smoke inhalation.
Crews were in attendance at the property for ninety minutes.
A spokesperson for the Lancashire fire and rescue service said: "Morecambe and Lancaster firefighters tackled a fire at a property on Morecambe Street West in Morecambe.
"The fire was on the ground floor of the property and fire crews extinguished it using two breathing apparatus, a hose reel and ventilation unit.
"Three casualties were taken to hospital for treatment for smoke inhalation. Crews were in attendance around ninety minutes."