Cap badge Dorset Regiment

The 1st Battalion was a regular army unit and part of the 231st Infantry Brigade, alongside the 1st Hampshires and 2nd Devonshires, for the duration of the war, fighting in Malta between 1940 and 1942, Sicily in August 1943, and Italy in September 1943. The 1st Dorsets landed on Gold Beach on D-Day in June 1944 as a part of the 50th (Northumbrian) Infantry Division and fought with the division in the Battle of Normandy and North-West Europe, until the division was withdrawn in late 1944 and used as a training division. The battalion had troops 327 killed and 1,029 wounded.

The 2nd Battalion was also a regular army unit and was part of the 5th Infantry Brigade, 2nd Infantry Division, throughout the war, participating in the Battle of France and the Dunkirk evacuation in 1940. In 1944, it took part in the Battle of Kohima during the Burma Campaign of 1944–1945, still with the 2nd Division.

The 4th Battalion was an original 1st Line Territorial Army unit and, in 1939, raised a 2nd Line duplicate, the 5th Battalion, when the Territorial Army was doubled in size prior to the commencement of the war. The 4th and 5th Battalions were both part of 130th Infantry Brigade in the 43rd (Wessex) Infantry Division, participating in the Normandy Campaign, Operation Market Garden and the Rhine Crossing.

The 30th Battalion, previously the 6th (Home Defence) Battalion, was with the 43rd Infantry Brigade in North Africa and the invasion of Sicily, after which it spent the rest of the war in Gibraltar.

The 7th Battalion, which was raised in 1940, was later converted to the 110th Light Anti-Aircraft Regiment, Royal Artillery. The regiment served with the 43rd (Wessex) Division in North-West Europe from June 1944 to May 1945.

The 8th Battalion, which was also raised in 1940, was initially assigned to the 210th Independent Infantry Brigade (Home) and was on home defence. Later, the battalion converted to the 105th Light Anti-Aircraft Regiment, Royal Artillery. The regiment was sent to North Africa in late 1942 and fought with the British First Army, It later served in the Italian Campaign with the British Eighth Army.