Online case listings show that Ancelotti, who is now in charge of Spanish giants Real Madrid, has taken High Court action against the Premier League club.
A claim has been filed in the commercial court, part of the High Court, in London and relates to “general commercial contracts and arrangements”.
The case is listed as Ancelotti v Everton Football Club Company Limited. Listings give no further details.
The 64-year-old Italian managed Everton between December 2019 and June 2021, before leaving to take up the role of head coach at Real Madrid.