Asser Mbai (born 1950 in Otjiwarongo) is a Namibian politician who has been President of the National Unity Democratic Organization (NUDO) since 2014, and a member of the National Assembly of Namibia since 2005. He succeeded Kuaima Riruako as President of NUDO after the latter's death on 2 June 2014.
He replaced Mburumba Kerina in the National Assembly following Kerina's following out with the party over the use of government funds. Prior to election to the National Assembly, he was a regional councillor for Okakarara.