Mastigias ocellatus, the golden medusa, is a species of jellyfish in the family Mastigiidae.

The surface of the bell is sculptured with small, polygonal nematocyst warts.

There are 96 marginal lappets and eight three-winged mouth arms, terminating in a bare, club-shaped extremity, the tip of which is blue.

The bell is reddish-brown, with white spots near the edge, each with a brown centre and margin.

[1][3] Mastigias ocellatus occurs in October in the southern Pacific Ocean.