John I of Thouars

John I of Thouars (born after 1284, died 1332) was the twenty-seventh viscount of Thouars, son of Guy II and Margaret of Brienne-Eu. In 1307 he married Blanche of Brabant, lady of Rochecorbon, younger daughter of Godfrey of Brabant. He succeeded his father in 1308 and ruled until he died.

Blanche died in 1330, leaving three sons. Louis I succeeded as viscount, John was lord of La Cheze-le-Vicomte, and Guy died in 1354.