Local Civil Defense director Juan Medina Sosa said 20 Mexicans, three Canadians and two Americans were injured, and all were in good condition.
The municipal government said in a statement that the victims sustained minor cuts and were taken to a hospital for treatment.
Dramatic video from the scene shows first responders rushing to the aid of patients, who were seen lying on the pier after the blast.
The Barcos Caribe vessel was left with a gaping hole in its starboard side next to a passenger seating area.
The municipal statement said the explosion happened when passengers were getting off the boat, and the cause was not yet known.
It added that service to the nearby resort island of Cozumel would continue with other ferry companies that operate from the municipal dock.
The Associated Press contributed to this report