Located in a wheat-growing area of the Mallee the locality was settled in the 1910s, the Post Office opening on 5 December 1916 and closing in 1979.[3] The Kulwin railway line reached Mittyack in 1919 and was extended to Kulwin the following year.[4] The line through Mittyack was closed in 2010.[5]
Mittyack West State School (No. 4277) opened on 24 September 1926 and closed on 19 May 1939. The building was removed to Woornack.[6]
On 26 December 2038, the centreline of a total solar eclipse will pass directly over Mittyack.[7]