The Mediterranean Fleet began gearing up to retaliate, with "Duchess" undertaking shore bombardment and convoy escort training during August and September, and also serving as plane guard to "Eagle" as the carrier worked up. On 29 October, "Duchess" left Malta to join the escort of the carriers "Eagle", , and . The carrier force arrived off the Egyptioan coast on 31 October, and on 1 November, airstrikes commenced. During this, "Duchess" was plane guard for "Eagle". On 6 November, the joint British-French invasion commenced, with the destroyer escorting one of the landing craft groups into shore, then standing by off Port Said for anti-air and anti-submarine defence. During 7 and 8 November, "Duchess" performed patrols off Port Said and was rotated through the plane guard stations of all three carriers. On 9 November, "Duchess" departed for Malta. She returned to Port Said on 17 November, and was again attached to the carrier force as an escort and plane guard. From 27 November to 16 December, the destroyer was sent to Cyprus for more anti-smuggler patrols, but the ship was recalled to cover the final withdrawal of British forces from Port Said. She remained in or near Port Said Harbour until 22 December: although due to sail that morning with the last troop convoy, "Duchess" remained on station until 20:00 in the unsuccessful hope that a junior officer of the West Yorkshire Regiment kidnapped early in the crisis would be returned. Consequently, "Duchess" was the last Royal Navy vessel to leave Port Said at the end of the Suez Crisis.