Megaceros is a genus of hornworts in the family Dendrocerotaceae.

The genus is found in the Old World tropics of east Asia and Australia.

[2] Its name means 'big horn', and refers both to the exceptionally large size of the gametophyte thallus and to the large, horn-shaped sporophyte that the plants produce.

Many species have a branching thallus that is more than two centimeters wide.

More recently, the genera Nothoceros and Phaeomegaceros have been split off from this genus.