News emerged on Monday morning that Chelsea have decided to sack Lampard following a run of just two wins in their last eight Premier League games.
Official confirmation is yet to arrive, but numerous outlets are reporting that the Blues have already struck a deal with Tuchel to replace their club-record goalscorer at the helm.
Tuchel has been out of work since being sacked by PSG at Christmas, but is now set for a swift return to management at Stamford Bridge.
Lampard will leave West London with a record of 44 wins from his 84 games in charge since taking over at the beginning of last season.
Lampard's record of 1.67 points per game is the fourth lowest of any permanent Chelsea boss in the Premier League era, while his average of 1.35 goals conceded per game is the worst in that time.
Tuchel, meanwhile, left PSG with the highest win percentage of any manager in Ligue 1 history.