Commandment Rock is a large rock located in the Lane Cove National Park, Sydney, New South Wales, Australia. The site is home to numerous rock engravings, both Aboriginal and European. An engraving of the Fifth Commandment on the rock gives it its name. It is reputed to have been carved in the late 19th century by a nearby resident, Thomas Tunbridge. Weathering has caused the engraving to be barely visible today. Other engravings include a cannon, anchor, axe, sword, bow and arrow, and a crescent and "sunburst" motif, the only two Aboriginal engravings at the site. Signs posted near the rock that once described the engravings have since been removed to avoid further traffic to the engravings and subsequent damage to the site.
The site is easy to access, located just next to the road and picnic area, although is not recommended to walk on the site, as this will increase the rate of erosion and destruction of the engravings.
In 1866 a family was living on the flat rock with a small vegetable and strawberry farm.