Niccolò I may refer to:

Niccolò I d'Este, Marquis of Modena and Ferrara (died 1344), see Duke of Ferrara and of Modena Niccolò I Ludovisi (1634–1664) Niccolò I Sanudo (died in 1341) Niccolò I Trinci (died in 1421)

See also

Nicholas I (disambiguation) Niccolò (name)