The division was sent to England on October 5, 1942. It was based throughout England and Scotland, where it immediately began training for an invasion of northern Europe across the English Channel.

In May 1943 the division moved to the Devon–Cornwall peninsula and started conducting simulated attacks against fortified positions. At this time it was assigned to V Corps of the First United States Army.

The cross-channel invasion of France finally came on June 6, 1944, Operation Overlord, the invasion of Normandy. The 29th Infantry Division sent the 116th Infantry Regiment to support the western flank of the 1st Infantry Division's 16th Infantry Regiment at Omaha Beach. Omaha was known to be the most difficult of the five landing beaches, due to its rough terrain and bluffs overlooking the beach, which had been well fortified by its German defenders of the 352nd Infantry Division.

The 116th Infantry Regiment was assigned four sectors of the beach; Easy Green, Dog Red, Dog White, and Dog Green. Soldiers of the 29th Infantry Division boarded a large number of attack transports for the D-Day invasion, among them Landing craft, Landing Ship, Tank and Landing Ship, Infantry ships and other vessels such as the SS Empire Javelin, USS Charles Carroll, and USS Buncombe County.

As the ships were traveling to the beach, the heavy seas, combined with the chaos of the fighting caused most of the landing force to be thrown off-course and most of the 116th Infantry missed its landing spots. Most of the regiment's tanks, launched from too far off-shore, floundered and sank in the channel.

The soldiers of the 116th Infantry began to hit the beach at 0630, coming under heavy fire from German fortifications. A Company, 1st Battalion, 116th Infantry was annihilated by overwhelming fire as it landed on the 116th's westernmost section of the beach, along with half of C Company, 2nd Ranger Battalion which was landing to the west of the 116th.

The 1st Infantry Division's forces ran into similar fortifications on the eastern half of the beach, suffering massive casualties coming ashore.

By 0830, the landings were called off for lack of space on the beach, as the Americans on Omaha Beach were unable to overcome German fortifications guarding the beach exits.

General Omar Bradley, commander of the First Army, considered evacuating survivors and landing the rest of the divisions elsewhere. However, by noon, elements of the American forces had been able to organize and advance off the beach, and the landings resumed.

By nightfall, the division headquarters landed on the beach with about 60 percent of the division's total strength, and began organizing the push inland. On June 7, a second wave of 20,000 reinforcements from the 1st and 29th divisions was sent ashore.

By the end of D-Day, 2,400 men from the two divisions had become casualties on Omaha Beach. Added to casualties at other beaches and air-drops made the total casualties for Operation Overlord 6,500 Americans and 3,000 British and Canadians, lighter numbers than expected.

The entire division had landed in Normandy by June 7. By June 9, Omaha Beach was secure and the division occupied Isigny. On July 14, the division was reassigned to XIX Corps, First United States Army, Twelfth United States Army Group.

The division cut across the Elle River and advanced slowly toward Saint-Lô, fighting bitterly in the Normandy hedge rows. German reserves formed a new defensive front outside the town, and American forces fought a fierce battle with them two miles outside of the town.

German forces used the dense bocage foliage to their advantage, mounting fierce resistance in house to house fighting in the ravaged Saint-Lô. By the end of the fight, the Germans were relying on Artillery support to hold the town following the depletion of the infantry contingent.

The 29th Division, which was already heavily underpower after heavy casualties on D-Day, was even further depleted in the intense fighting for Saint-Lô. Eventually, the 29th was able to capture the city in a direct assault, supported by airstrikes from P-47 Thunderbolts.

After taking Saint-Lô, on July 18, the Division joined in the battle for Vire, capturing that strongly held city by August 7. it continued to face stiff German resistance as it advanced to key positions southeast of Saint-Lô.

It was then reassigned to V Corps, and then again to VIII Corps. Turning west, the 29th took part in the assault on Brest which lasted from August 25 until September 18.

After a short rest, the division returned to XIX Corps and moved to defensive positions along the Teveren-Geilenkirchen line in Germany and maintained those positions through October. On November 16, the division began its drive to the Roer River, blasting its way through Siersdorf, Setterich, Durboslar, and Bettendorf, and reaching the Roer by the end of the month. Heavy fighting reduced Jülich Sportplatz and the Hasenfeld Gut on December 8.

From December 8, 1944 to February 23, 1945, the division was assigned to XIII Corps and held defensive positions along the Roer and prepared for the next major offensive. The division was reassigned to XIX Corps, and the attack jumped off across the Roer on February 23, and carried the division through Jülich, Broich, Immerath, and Titz, to Mönchengladbach by March 1, 1945.

The division was out of combat in March. In early April the division was reassigned to XVI Corps, where 116th Infantry helped mop up in the Ruhr area. On April 19, 1945 the division, assigned to XIII Corps, pushed to the Elbe River and held defensive positions until May 4.

Meanwhile, the 175th Infantry cleared the Klotze Forest. After V-E Day, the division was on military government duty in the Bremen enclave. It was assigned to XVI Corps again for this assignment.

The division remained on occupation duty until the end of 1945. It returned to the United States in January 1946 and was demobilized and deactivated on January 17, 1946 at Camp Kilmer, New Jersey.

During World War II, the 29th Infantry Division suffered 3,720 killed in action, 15,403 wounded in action, 462 missing in action, 526 prisoners of war, and 8,665 non-combat casualties, for a total of 28,776 casualties during 242 days of combat. This amounted to over 200 percent of the division's normal strength.

The division, in turn, took 38,912 German prisoners of war. Soldiers of the 29th Infantry Division were awarded two Medals of Honor, 44 Distinguished Service Crosses, one Distinguished Service Medal, 854 Silver Star Medals, 17 Legion of Merit Medals, 24 Soldiers' Medals, 6,308 Bronze Star Medals, and 176 Air Medals during the conflict. The division itself was awarded four distinguished unit citations and four campaign streamers for the conflict.