The fire started in a second-floor hallway of the Radisson Hotel around 8 a.m. Thursday, the Ottawa Sun reported.
Police said 105 people were evacuated, some of whom broke windows to escape, the Ottawa Citizen said. Among them were two boys' hockey teams from China and one from Germany visiting the city for an international tournament.
Of the five people injured, the most serious was an unidentified woman with second-degree burns to 20 percent of her body, the Citizen said.
It took firefighters about 30 minutes to put out the fire, which they estimated caused $1 million in damage.
The Ontario fire marshal's office was notified when police discovered a spray can and a gas can where the fire started, along with a backpack containing clothing in an elevator, the Citizen said.