The foramen rotundum is a circular hole in the sphenoid bone of the skull.

The foramen rotundum is one of the several circular apertures (the foramina) located in the base of the skull, in the anterior and medial part of the sphenoid bone.

The mean area of the foramina rotunda is not considerable, which may suggest that they play a minor role in the dynamics of blood circulation in the venous system of the head.

[1] The foramen rotundum evolves in shape throughout the fetal period, and from birth to adolescence.

This article incorporates text in the public domain from page 150 of the 20th edition of Gray's Anatomy (1918)