The 89th Light Anti-Aircraft Regiment, Royal Artillery, (89th LAA Rgt) was an air defence unit of the British Army during World War II.

The unit was originally formed in January 1940 as a company of 14th (Holding) Battalion at Tonbridge in Kent, as part of the rapid expansion of the Army with wartime conscripts.

Now, returned to the UK, it had been reorganised in Western Command and was training for the planned Allied invasion of Normandy (Operation Overlord).

Then at the end of the month it moved to a concentration area to take part in Exercise Spartan (3–15 March), after which it returned to Pembroke Dock.

[18][19] On 1 June 1943 Regimental Headquarters (RHQ) moved to Rustington in Sussex where the batteries took over ADGB operational sites at Littlehampton, Bognor Regis and Farnborough, Hampshire.

On 21 June RHQ moved to Wakes Colne in Essex and took over ADGB sites at Thames Haven, Ipswich, Frinton-on-Sea, Clacton-on-Sea and Walton-on-the-Naze.

[23] Exercise Bridgehead was held during October, after which the batteries began attending courses at the Combined Operations Training Centre at Inverary.

The infantry attacked at 04.15 through fields of crops with tank support behind a Creeping barrage and fought their way into Fontenay-le-Pesnel, but they had been disorganised by early morning mist, ran into fierce opposition, and although they held off a strong counter-attack, they ended the day about 1 mile (1.6 km) short of Rauray.

LAA units fired tracer to guide night attacks onto their objectives, and the Bofors guns were much in demand for infantry support.

[10] When the breakout from the Normandy beachhead finally began, the division fought its way down towards Falaise, and then swung east as First Canadian Army advanced along the coast to clear the Channel ports.

At the end of this spell, Bobforce advanced under covering fire from Bofors guns and drive the enemy rearguards back 3 miles (4.8 km).

[41][42][43] The division was then switched eastwards, where it came under XII Corps and was stationed facing the heavily fortified town of Blerick, which was the last significant German bridgehead on the west bank of the Maas.

On 28 November it was relieved by 15th (Scottish) Infantry Division, which was to carry out the actual assault (Operation Guildford), while 49th went to 21st Army Group's own bridgehead over the River Waal at Nijmegen under II Canadian Corps.

The German 6th Parachute Division then made a ground attack on the Nijmegen bridgehead, infiltrating between the isolated British positions, but was driven out.

Aircraft appeared all over 21st Army Group's area, suffering heavy casualties: GHQ AA Troops reported that '40 mm LAA had the time of its life'.

[49] Nijmegen bridge was strongly attacked from the air on 8/9 February, but the LAA fire in the area was effective in preventing serious damage.

[53][54] In late April there was a ceasefire in the Northern Netherlands while food supplies were air-dropped to the Dutch population in the area still under German occupation (Operation Manna).