Cosmocampus balli (Ball's pipefish) is a species of fish of the family Syngnathidae.

[1] It lives in shallow, protected coral reef or rocky habitats, where it can grow to lengths of 7 centimetres (2.8 in).

Although little is known about its feeding habits, it is expected to consume small crustaceans, similar to other pipefishes.

This species is ovoviviparous, with males carrying eggs and giving birth to live young.

[2] The specific name honours the American zoologist Stanley Crittenden Ball (1885-1956) in acknowledgement of his "interest in the fishes of Oceania".