Bahau is a state constituency in Negeri Sembilan, Malaysia, that has been represented in the Negeri Sembilan State Legislative Assembly. The state constituency was first contested in 1959 and is mandated to return a single Assemblyman to the Negeri Sembilan State Legislative Assembly under the first-past-the-post voting system. Since 2018, the State Assemblyman for Bahau is Teo Kok Seong from the Democratic Action Party (DAP), which is part of the state's ruling coalition, Pakatan Harapan (PH).