The word may have one of the following meanings.

• In Greek mythology, Nestor was the son of Neleus, the King of Pylos and Chloris. See Nestor (mythology).

• Nestor is also a archaeological site and a municipality in the west-southwestern part of Messenia

• Nestor the Chronicler is a compiler of the Primary Chronicle of the East Slavic peoples.

• In Ornithology, Nestor is a genus of parrots.

• Nestor is a fictional character from Belgian artist Hergé's renowned Tintin comic strip books.

• In the Star Trek universe, a Nestor is a legal advisor to the offender in Cardassian criminal trials. Unlike the defense lawyer, the Nestor is barred from directly addressing the tribunal.

• In the book I, Robot and the movie I, Robot, Nestor is the common nickname of NS-series robots.