Victory over Sheffield Wednesday on Friday evening put City in a very strong position at the top of the Championship table as they chased a return to the top flight after a 10-year absence. When two rivals then dropped points on Saturday, their place in one of the two automatic promotion places was confirmed.
City still have six games remaining in the season and are now chasing the Championship title.
Leicester Tigers chief executive Simon Cohen said: “We offer our congratulations to Leicester City’s player and to manager Nigel Pearson on their promotion back to the Premier League.
“Leicester is a major sporting city and to have another of our professional clubs playing at the top level of their sport is great news for the city, the region and the community as a whole. Winning promotion is a very proud achievement for the club and their supporters, and we hope they can now go on to also win the Championship league title.”