Surinder Singh, the AAP MLA from Delhi Cantonment, was also sworn in along with Kejriwal at a special meeting of the Council.
According to the NDMC Act, MLAs from these two constituencies automatically become members of the Council.
NDMC chairperson Jalaj Srivastava administered the oath of membership to Kejriwal. Singh was then sworn in by Kejriwal himself.
Kejriwal said that AAP party was against corruption and hoped that "NDMC will cooperate in this aim of the party".
He also asked the Council to take note of the genuine concerns and demands of its employees.
The chief minister was later given a presentation on the functioning of NDMC, its hierarchy and brief about its various departments.