The German company said no injuries or deaths were reported relating to the vehicles that it will begin recalling in the U.S. market in July when parts become available.
A fix has been implemented in the production of new vehicles and vehicles on dealers lots will be fixed before they are sold, the company said. The issue relates to a potentially faulty fuse.
"Any affected vehicles in inventory will not be sold until they can be outfitted with the additional fuse," said a Mercedes-Benz spokesman.
Of the million vehicles to be recalled, 307,629 are in the United States, which is 40,000 units less than Mercedes-Benz reported to U.S. regulators.
The company did not immediately have a breakdown of where vehicles will be recalled outside of the United States.
The United States is among the three biggest markets for Mercedes-Benz, the others being China and Germany.
Of the 51 fires, 30 were reported in the U.S. market, a Mercedes-Benz U.S. spokesman said.
The recall affects newer models, including those from the 2017 model year.
Mercedes-Benz and Daimler said it would begin to notify its U.S. customers late in March. It didn't say when owners in other markets would be notified.