Both teams have had an outbreak of COVID-19 in their camps.
The match against Tottenham was scheduled to kick off at 19:30 at the King Power Stadium.
A statement from Leicester City said: " The decision was taken with guidance from medical advisors after the Club resubmitted its application for postponement after confirmation this morning (Thursday) of further positive tests for COVID-19 within the First Team squad. As a result, the Club has an insufficient number of First Team players available to fulfil the match.
Leicester City can confirm that the Premier League Board has decided to postpone Thursday night’s fixture against Tottenham Hotspur.
— Leicester City (@LCFC) December 16, 2021
"Given the increase in positive tests among First Team personnel, First Team operations at Seagrave will now be closed for 48 hours, serving as a circuit breaker to help reduce the risk of further infection. First Team players and staff will undergo a subsequent round of testing on Saturday.
The Club regrets the inconvenience caused to Tottenham Hotspur and both sets of supporters by Thursday night’s postponement."