It is a benthic fish of shallow, rocky water on the coasts of the eastern Atlantic Ocean and the western Mediterranean Sea.

Its colour is variable; it is frequently green with darker mottling, or reddish-brown dotted with dark brown, and it has large white dorsal spots.

[4] Apletodon dentatus is found in the eastern North Atlantic Ocean and the western Mediterranean Sea.

[1] Apletodon dentatus occurs in the tidal and subtidal zones where it is associated with submerged vegetation such as the sea grass Posidonia oceanica off France, with beds of the large brown algae of the genus Cystoseira off Sicily, and with rocky areas with brown algae.

This species has also been recorded among turf-like growths of the alga Gelidium latifolium, it associates with the sea urchins Paracentrotus lividus and Sphaerechinus granularis, and then among boulders.