Theo van Gogh, Dutch art dealer (d. 1891)
Theodorus van Gogh (Dutch pronunciation: [teːjoːˈdoːrʏs ˈteːjoː vɑŋ ˈɣɔx]; 1 May 1857 – 25 January 1891) was a Dutch art dealer. He was the younger brother of Vincent van Gogh, and Theo's unfailing financial and emotional support allowed his brother to devote himself entirely to painting. Theo died at the age of 33, six months after his brother died at the age of 37.

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 played a crucial role in the introduction of contemporary Dutch and French art to the public.