John I of Namur (1267 – January 31, 1330) is the ruler of Namur from 1305 to 1330.

He is a member of the House of Dampierre, the son of Guy of Dampierre, Count of Flanders and Marquis of Namur, and his second wife Isabelle of Luxembourg.

John is the father of Blanche of Namur, Queen of Sweden and Norway.