Operation Windsor (4–5 July 1944), was a Canadian attack of the Battle of Normandy during the Second World War. The attack was undertaken by the 3rd Canadian Infantry Division to take Carpiquet and the adjacent airfield from troops of the 12th SS-Panzer Division Hitler Jugend of Panzergruppe West. The attack was originally intended to take place during the later stages of Operation Epsom, to protect the eastern flank of the main assault but was postponed for a week.

On 4 July, the 8th Canadian Infantry Brigade and an attached battalion of the 3rd Canadian Infantry Division attacked Carpiquet, supported on the flanks by the 2nd Canadian Armoured Brigade. The village was captured by mid-afternoon but German resistance in the south defeated two attacks on the airfield, despite significant Allied tank and air support. Next day the Canadians repulsed German counter-attacks and held the village, which served as a base for Operation Charnwood, a Second Army attack on Caen, involving the rest of the 3rd Canadian Infantry Division on 8 July, and the airfield was captured by the Canadians on 9 July.

Caen was an Operation Overlord goal for I Corps of the Anglo-Canadian Second Army, which landed forces on two Normandy beaches on 6 June 1944, to capture the city and the Carpiquet area. German resistance prevented the town from being captured on D-Day, a result considered possible by Lieutenant-General Miles Dempsey the Second Army commander. For the next three weeks, positional warfare took place around Caen as both sides attacked and counter-attacked for minor tactical advantage on the Anglo-Canadian front and as part of a strategic intent to force the Germans to keep their most powerful armoured units away from the US First Army, as it captured Cherbourg and then pushed southwards through the bocage towards St. Lô.

From 26–30 June, the Second Army conducted Operation Epsom, with the VIII Corps which had recently arrived from Britain, to outflank Caen from the west and seize the high ground across the Orne near Bretteville-sur-Laize to the south. VIII Corps advanced 6 mi (9.7 km) through extensive field fortifications but the Germans were able to contain the offensive, after committing their last reserves. Depending on the success of VIII Corps, the 3rd Canadian Infantry Division and the 2nd Canadian Armoured Brigade were to capture the village and airfield of Carpiquet in Operation Ottawa, which was postponed.

After the Allied advance to the west of Caen, the I SS Panzer Corps held positions to the north and west of the city. Field defences on the River Orne and the vicinity of Carpiquet, 3.5 mi (5.6 km) north-west of the Caen town centre, obstructed an advance toward Caen from the north. The village was made an objective of the 3rd Canadian Infantry Division, under the command of Major-General R. F. L. Keller. The Allied need for additional airfields on the Normandy mainland, ensured that the capture of the Carpiquet area was a priority for the Allies and an equally important defensive position for the Germans.

Carpiquet airfield was on a 1.2 mi (1.9 km) expanse of level ground, which offered a "killing ground" for the defenders. The airfield had been fortified with minefields, field gun and machine gun emplacements, manned by I Battalion, SS-Panzergrenadier Regiment 26, an anti-aircraft battery and fifteen tanks.

Keller selected the 8th Canadian Infantry Brigade, comprising The Queen's Own Rifles of Canada (QOR), Le Régiment de la Chaudière and The North Shore (New Brunswick) Regiment; The Royal Winnipeg Rifles (RWR) were attached from the 7th Canadian Infantry Brigade to lead the assault. Tank and machine-gun support was to be provided by the 10th Armoured Regiment (The Fort Garry Horse), The Sherbrooke Fusiliers and the Cameron Highlanders Support Battalion. Two squadrons of Hawker Typhoon fighter-bombers and three squadrons of specialized tanks from the 79th Armoured Division were added later. On the evening of 3 July, the battleship HMS Rodney bombarded the buildings around Carpiquet from the Bay of the Seine at 26,200 yd (24,000 m) range, with fifteen shells from its 16 in (410 mm) guns.

Operation Windsor was planned to commence at 05:00 on 4 July, following a bombardment by 21 artillery regiments, with Le Régiment de la Chaudière and The North Shore Regiment attacking Carpiquet, as a squadron of the Sherbrooke Fusiliers protected the northern flank with a diversionary attack on Franqueville. To the south, the RWR was to advance and seize the hangars of Carpiquet airfield. At the same time as the Canadian attack, the 43rd Division was to attack further south down the north side of the Odon to capture Verson. Once the regiments had captured Carpiquet, the QOR would push through and take control of the airfield control buildings. The capture of the airfield would enable further Anglo-Canadian attacks against Caen.