A spokesperson for the cathedral said the fire, which comes as French Catholics prepare to celebrate Easter, broke out at around 16:50 GMT where the smoke and flames plumed from the cathedral.
Police and ambulance cars rushed to the scene, while the police twitted warning persons to distance from the surrounding of the cathedral.
"A terrible fire is under way at Notre-Dame Cathedral in Paris,” Mayor Anne Hidalgo said on Twitter.
President Emmanuel Macron cancelled a televised statement due to deliver on Monday evening. A presidential official said Macron was to head to the scene of the blaze.
Moreover, the French authorities have begun to evacuate the environs of the cathedral.
While US president Trump twitted, “So horrible to watch the massive fire at Notre-Dame Cathedral in Paris. Perhaps flying water tankers could be used to put it out. Must act quickly!”.