Angeloni was appointed in June last year along with former director of football Roberto De Fanti following the departure of Bryan Robson.
However, the duo, who had previously worked together at Udinese and Inter, have been widely criticised for their transfer dealings in the close-season.
A total of 14 players arrived before the start of the current campaign, but few have had a positive impact during the season, with midfielder Cabral and defender Modibo Diakite both going out on loan after failing to establish themselves in the first team.
Sunderland's lack of success in the transfer market led to De Fanti being relieved of his duties in January, and Angeloni has now followed him through the exit door at the Stadium of Light.
A statement on Sunderland's official website read: "Sunderland AFC has confirmed that Valentino Angeloni has left the club and the club places on record its thanks to Valentino."
