In the past, the district was called Wat Pradu District because the office was in front of
Wat Pradu, Wat Pradu canal. When the district office was moved to the present area, the district name was changed to be
Maenam Om district. Later in 1914 the government moved the district office of Maenam Om to Tambon Pak Tho, which was more accessible as it was near the railway station. The old central area was made the Wat Phleng minor district (
king amphoe). It was upgraded to a full district again on 17 July 1963. ==Geography==