Castello di Bosco di Corniglio, Medieval castle in Corniglio, Italy.

Castello di Bosco di Corniglio, also called Castello di Bosco, is a ruined hilltop castle in the hamlet of Bosco di Corniglio, in the municipality of Corniglio, province of Parma. Built in 1400, it was contested by the Terzi and Fieschi families. Today only the remains of a tower and parts of the perimeter wall are visible.

The castle was built in 1400 and became a battleground between the Terzi and Fieschi families. In 1413 it appears as a Rossi possession in Emperor Sigismund's diploma; in 1431 the Visconti took it, and ten years later Pietro Maria Rossi bought it back for 9,600 imperial lire. In 1464 Pier Maria II de' Rossi left it to his son Bertrando, but on 1 September 1482 Obietto Fieschi seized it after the castellan Michele Bajardi di Calestano betrayed him. The Farnese confiscated it in 1593, and by 1804 only foundations and one tower remained.

The name "alto Bosco" appears in the sonnet Cantilena pro potenti D. Petro Maria Berceti Comite by the poet Gerardo Rustici, written while the castle was held by the Rossi. The verse records the stronghold under the Rossi as a high, wooded site, and the name survives only through this literary mention.

The castle ruins are accessible via Strada Vicinale del Castello and offer a hiking route through elevated terrain. Sturdy footwear is recommended as the paths can be uneven and facilities on site are minimal.

On 1 September 1482 Obietto Fieschi, allied with Ludovico il Moro against the Rossi, besieged the castle with three squads of armed men and took it without artillery: the castellan Michele Bajardi di Calestano, whom Pier Maria II de' Rossi had put in charge of the defences, betrayed him. The Fieschi kept the fief until 30 November 1521.