A Matthew Walker knot is a decorative knot that is used to keep the end of a rope from fraying. It is tied by unraveling the strands of a twisted rope, knotting the strands together, then laying up the strands together again.

It is not specifically known who Matthew Walker was, nor why this knot was named for him. However, early references from the 19th century suggest he may have been a ship's rigger in the Royal Navy.