Teófilo Castillo Guas or Guash (2 October 1857, Carhuaz – 7 December 1922, Tucumán) was a Peruvian Impressionist painter, art critic and photographer.

Teófilo Castillo Guas, or Guash, was born on 2 October 1857, in Carhuaz in the Ancash Region, Peru.

He also became artistic director for the magazines Prisma, La Ilustración Peruana and Variedades, where he published color reproductions of his major works.

[2] He was an enthusiastic promoter for the establishment of the Escuela Nacional Superior Autónoma de Bellas Artes (now National Superior Autonomous School of Fine Arts, Lima), and he recommended Daniel Hernández Morillo as the most qualified person to become the school's first Director.

[1] He also produced a huge canvas depicting General Manuel Belgrano presenting the Flag of Argentina to the Congress of Tucumán in 1816, which was purchased by the Argentine government for 20,000 Pesos.