The troops, drawn from the UK Standby Battalions based at Catterick (Light Dragoons) and Cottesmore (2 Royal Anglian), will assist civilian authorities on the ground by bolstering flood defences in the Doncaster and River Don area.
If necessary, soldiers will also provide help with warning and informing residents, and support with potential evacuation efforts from high risk or flooded areas.
Lt Col John Holden (Joint Regional Liaison Officer for Yorkshire and the Humber) said: “Personnel deployed early this morning and have been on the scene giving important support to communities following flooding over recent days.
“The British Army has the resource and versatility to tackle any task it’s called in for, and will continue to assist as required.”
Following this morning’s deployment a further 200 personnel will be put on immediate readiness later today, and Defence and the Armed Forces will continue to stay in close communication with other authorities to assess the requirement for further personnel if needed.
The deployment of troops follows support provided at the weekend by the Royal Air Force, when RAF Chinooks were called in to assist a pumping station near Doncaster following heavy rainfall.
The aircraft dropped 40 tonnes of aggregate at specific points to ensure flood defences could continue to work properly.