American sculptor notable for his technique of direct carving and for his sculptures of animals, birds, fish, and birth themes.

Trained as a painter at the Minneapolis (Minnesota) Institute of Arts, Flannagan eventually moved to New York City, where he was encouraged by Arthur B. Davies (Davies, Arthur B.) to take up wood carving. For five years he worked almost exclusively in this medium. While living in upstate New York, he first became attracted to the natural beauty of fieldstone: he went on to work for many years in this medium. Flannagan explored his subconscious for inspiration and also let the shape of a stone itself suggest the subject of a piece.

The traumatic process of coming into being was Flannagan's most effective poetic theme; it informed his major works—e.g., Triumph of the Egg (1937 and 1941) and perhaps even the tumid Dragon Motif (1933). The spirit of the inert material seems to emerge from these works and mingle with the impressions made by the carver. Shortly before he committed suicide, Flannagan had begun to work in wrought bronze.