Popularized by the character Homer Simpson in the TV show the Simpsons (there spelled d'oh). The OED has references from the BBC as far back as 1945, however.
An anglicised spelling of do.
"doh." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/doh>.
doh. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/doh