A handmade granny square baby blanket is a type of crochet blanket that is made up of individual granny squares, which are small crochet squares typically composed of a combination of double crochet and chain stitches. These granny squares are then sewn or crocheted together to create a larger blanket.

The term "granny" in the name comes from the fact that the pattern is often associated with older generations, who would frequently crochet these squares and join them together to make warm, cozy blankets. The pattern is popular for its simplicity, versatility, and ability to use up leftover yarn scraps.

A granny square baby blanket is typically made with soft, baby-friendly yarn and is sized appropriately for a baby or toddler. The blankets can be made in a variety of colors and patterns, depending on the maker's preferences, and they make a great handmade gift for new parents or for baby showers.