The Election Commission had Oct 25 announced that Mehrauli, Tughlakabad and Krishna Nagar would go to the polls Nov 25. BJP legislators from the three places were elected to the Lok Sabha in May.
Delhi has been under President's rule since Feb 17 following the resignation of chief minister Arvind Kejriwal, who headed a minority Aam Aadmi Party government for 49 days.
A Rashtrapati Bhawan spokesperson said the President has signed the proclamation dissolving the Delhi assembly.
The union cabinet Tuesday recommended the dissolution of the 70-member Delhi assembly where no political party had enough numbers to form a stable government.
The decision was taken after leaders of the Bharatiya Janata party, AAP and the Congress told Lt. Governor Najeeb Jung that they wanted elections to end months of political uncertainty.
The Delhi election of December 2013 threw up a fractured mandate.