COL19A1 (collagen type XIX alpha 1 chain) is a secreted component of the extracellular matrix. The collagen alpha-1(XIX) chain is proposed to act as a cross-bridge between fibrils and other extracellular matrix molecules, and may contribute to the organisation of the pericellular matrix or of sphincteric smooth muscle. It has also been implicated in skeletal myogenesis in the developing oesophagus.

The COL19A1 gene encodes the alpha chain of type XIX collagen and belongs to the FACIT family, the fibril-associated collagens with interrupted triple helices. This is the HGNC gene group to which it is assigned. Other FACIT members are found in association with fibril-forming collagens such as types I and II, where they help maintain the integrity of the extracellular matrix. The precise function of type XIX collagen itself is not established, so the roles above are described with caution in the literature.

The gene was formerly named collagen, type XIX, alpha 1. According to the NCBI Gene summary, its transcript has an unusually large 3' UTR that has not been completely sequenced. The mouse ortholog is Col19a1. Researchers studying COL19A1 typically do so in the context of matrix organisation, muscle development and the wider collagen superfamily.