Theodorus "Theo" van Gogh (May 1, 1857 – January 25, 1891) is a Dutch art dealer.

He is the younger brother of Vincent van Gogh, and Theo's unfailing financial and emotional support allows his brother to devote himself entirely to painting.

Theo dies at the age of thirty-three, six months after his brother dies at the age of thirty-seven.

Theo is widely known for his influence on his brother; however, this often overshadows the significant impact that Theo made on the art world as a renowned art dealer: Theo playa a crucial role in the introduction of contemporary Dutch and French art to the public.