Ancelotti was appointed as head coach of Napoli in May 2018, signing a three-year contract to replace Chelsea-bound Maurizio Sarri.
In his first season, the 60-year-old guided the Naples based club to a familiar second place finish in Serie A behind Juventus.
Prior to their win against Genk, Napoli had gone nine matches without victory in all competitions, a poor run of form which started after a 3-2 win over Red Bull Salzburg in October.
According to Sky Italia, the former Real Madrid manager revealed that he had no intention of resigning during his post-match conference.
A Napoli club statement confirmed the Italian tactician’s departure few hours after the club’s victory over Genk.
"SSC Napoli has decided to revoke the role of first-team coach from Mr. Carlo Ancelotti,” the statement read.
"The rapport of friendship, admiration and reciprocal respect between the club, its president (Aurelio De Laurentiis) and Carlo Ancelotti remain intact."
As per reports in Italy, former AC Milan manager Gennaro Gattuso is in contention to replace Ancelotti at Napoli.
Premier League clubs like Arsenal and Everton are considering the Italian to take over as manager following the sacking of their respective coaches.
Ancelotti is one of the top managers in the world having coached teams like Juventus, AC Milan, Bayern Munich, Chelsea and Paris Saint-Germain.