The splenius capitis (/ˈspliːniəs ˈkæpɪtɪs/) (from Greek splēníon 'bandage' and Latin caput 'head'[1][2]) is a broad, straplike muscle in the back of the neck.

The fibers of the muscle are directed upward and laterally and are inserted, under cover of the sternocleidomastoideus, into the mastoid process of the temporal bone, and into the rough surface on the occipital bone just below the lateral third of the superior nuchal line.

The splenius capitis is deep to sternocleidomastoideus at the mastoid process, and to the trapezius for its lower portion.

The splenius capitis muscle is innervated by the posterior ramus of spinal nerves C3 and C4.

This article incorporates text in the public domain from page 397 of the 20th edition of Gray's Anatomy (1918)