| Radial notch | |
| Latin: | incisura radialis ulnae |
| Width: | 200 |
The radial notch of the ulna (lesser sigmoid cavity) is a narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the circumferential articular surface of the head of the radius.
It is concave from before backward, and its prominent extremities serve for the attachment of the annular ligament.