San Nicola is a church in Ottana, central Sardinia, Italy. Dedicated to St. Nicholas of Myra, it was consecrated in 1160. It is located on a hill commanding the town and is reached through a staircase.
The interior houses a 16th-century wooden crucifix and a 14th-century polyptych, known as Ottana Altarpiece. It is attributed to a "Master of the Franciscan tempera", active in Naples between 1330 and 1345. Among other figures, it portrays the then hereditary giudice of Arborea, Mariano IV of Arborea.