IC 2391 (also known as the Omicron Velorum Cluster or Caldwell 85) is an open cluster in the constellation Vela consisting of hot, young, blueish stars, some of which binaries and one of which is a quadruple.

It contains about 30 stars with a total visual magnitude of 2.5, spread out along 50 arcminutes.

It includes these members:[4] The stars' era of formation is similar to open cluster IC 2602 in neighbouring Carina,[23] and has a lithium depletion boundary age of about 50 million years.

[25] The components formed at about the same time as a nearer group, known as the "Argus Association" which one motion model suggests began in their own nebula cloud.

These are in a similar direction, roughly the Vela constellation, within the local galactic arm.