Grand Chief Derek Nepinak (NEE'-pih-nack) of the Assembly of Manitoba Chiefs also says he is planning to sue for defamation.
Brad Badiuk, a technology teacher at Kelvin High School, was placed on leave last week and is being investigated by the Winnipeg School Division.
Posts on a Facebook page under Badiuk's name described aboriginals as lazy people who are seeking money from non-aboriginals.
Attempts to reach Badiuk for comment have been unsuccessful and the Facebook page has been taken down.
The school division has said Badiuk must be given due process and the investigation could take some time, but Nepinak is calling for the teacher's immediate dismissal.
"To think that there could be children being subjected to this kind of thinking is appalling, and we have a responsibility to seek the full scope of available sanctions against persons making racist and hateful statements towards our children", Nepinak said in a written statement.