After the Allies conquered Sicily, their next step was the invasion of mainland Italy. From 31 August "Troubridge" took part in Operation Baytown, their landings in Calabria, escorting the bombardment force and providing artillery support herself, while on 9 September she took part in Operation Avalanche, the Allied landings at Salerno, where she formed part of the covering force. In early 1944, the 24th Flotilla moved to the Adriatic, with "Troubridge" carrying out bombardment operations against targets on the Dalmatian coast and the island of Korčula. On 15 August 1944, the Allies invaded the South of France, with "Troubridge" forming part of the screen for the Escort carriers of TG88.1, which were providing air cover for the landings. In September 1944 "Troubridge", with the rest of her flotilla, returned to the Aegean, where they were employed in interfering with the German evacuation of the Greek islands. On 13 September "Troubridge" and sister ship sank the cargo ship , while on 19 September "Troubridge", , and the Polish destroyer ORP "Garland" depth-charged and sank the German submarine south of Milos, in position 36°27'N, 24°33'E.