Clinker boat building is a method of constructing hulls for boats and ships by fixing wooden planks to a frame so that the planks overlap each other gaining support from the frame and from adjacent planks. The technique was first used by the Vikings.

Narrow planks are fixed to a frame of "ribs" which are first mounted on a heavy keel. The downward edge of each plank overlaps the plank below it. The overlapping edges are bevelled to create a tight fit. The overlaps generally taper to nothing at the ends of the boats.

The planks are fastened together in several ways:

• with copper rivets consisting of a square nail and a dish shaped washer called a rove
• with iron nails with the protruding ends bent over and back into the wood in a technique called clenching . Clench built is another term for this technique.
• screws
• adhesive, notably epoxy

Clinker boats are known for their lightness and flexibility.

It is commonly linked to the Vikings who used this method to build their famous ships from split wood planks. Clinker is the British term, it is known as lapstrake in North America.

Clinker boat building was used in Europe and the Americas for centuries, even after the development of the more efficient carvel style.