Please note that this list may or may not be exhaustive. I would welcome any input from knowledgeable parties.
Regiments/Units Involved

South African Yeomanry scouting a Boer-held farm
Aberdeen Town Guard
Adelaide District Mounted Troops
Ashburner’s Light Horse
Barkley West Town Guard
Bayly’s Horse
Beaconsfield Town Guard
Beaufort West Town Guard
Bechuanaland Police
Bechuanaland Rifle Volunteers
Bechuanaland Protectorate Regiment
Bedford District Mounted Troops
Beddy’s Scouts
Bethune’s Mounted Infantry
Border Mounted Police
Border Mounted Rifles
Border Horse
Border Scouts
Brabant’s Horse
Brett’s Scouts
British South African Police
Bushmanland Borderers
Bush Veldt Carbineers
Byng’s Scouts
Cape Colony Cyclist Corps
Cape Colony Defence Force
Cape Medical Staff Corps
Cape Garrison Artillery
Cape Infantry
Cape Mounted Rifles
Cape Mounted Police
Cape Railway Capetown Highlanders
Ceres Scouts
1st City Volunteers (Marshall’s Horse)
City of Grahamstown Volunteers
Clifford’s Scouts
Colonial Light Horse
Bodyguard Corps of Cattle Rangers
Cradock Town Guard
Cullinan’s Horse
Damant’s Horse
De Aar Town Guard
De Beers Maxim Battery
Dennison’s Scouts
Diamond Fields Horse
Diamond Fields Artillery
District Military Police
District Mounted Troops
Dordrecht Dictrict Volunteer Guard
Dordrecht Wodehouse Yeomanry
Driscoll’s Scouts
Duke of Edinburgh’s Own Volunteer Rifles
Durban Light Infantry
Eastern Province Horse
Eastern Transvaal Scouts
East Griqualand Mounted Rifle Volunteers
East Griqualand Field Force
Edwards’s Scouts
Farmers’ Guard
Fraserburg District Mounted Troops
French’s Scouts
Frontier Light Horse
Frontier Mounted Rifles
Geoghegan’s Scouts
George District Mounted Troops
Gorringe’s Flying Column
Heidelberg Volunteers and Scouts
Herschel Special Police
Herschel Native Police
Imperial Light Horse
Imperial Light Infantry
lndwe Town Guard
Jamestown Town Guard
Jansenville District Mounted Troops
Jansenville Town Guard
Johannesburg Mounted Rifles
Johannesburg Police
Kaffrarian Rifles
Kenhardt Town Guard
Keeley’s Vryburg Farmer’s Association
Kimberley Light Horse
Kimberley Regiment
Kimberley Town Guard
Kimberley Mounted Corps
Kitchener’s Horse
Kitchener’s Fighting Scouts
Klipdam Town Guard
Knysna Rangers
Kofflefontein Defence Force
Komga Mounted Infantry
Kroonstad Scouts
Laingsburg Town Guard
Loch’s Horse
Lower Rhodesian Volunteers
Loyal Burgher Corps
Loxton’s Horse
Lydenburg Civil Mounted Rifles
Maritzani Mounted Irregulars
Murray’s Horse
Mafeking Town Guard
Menne’s Scouts
Midland Mounted Rifles
Middelburg Town Guard
Molteno Town Guard
Montagu Town Guard
Montmorency’s Scouts
Morley’s Scouts
Mossel Bay Town Guard
Namaqualand Border Scouts
Namaqualand District Mounted Police
Namaqualand Town Guard
National Scouts
Natal Volunteer Field Artillery
Natal Volunteers Police and Guides
Natal Bridge Guards
Natal Carbineers
Natal Police
Natal Mounted Rifles
Natal Naval Artilery
Natal Police
NataI Royal Rifles
Natal Volunteer Composite Regiment
Nesbitt’s Horse
New England Mounted Rifles
Orange River Colony Police
Orange River Colony Volunteers
Orpen’s Horse
Oudtsdhoorn Volunteer Rifles
Peninsular Horse
Pietersburg Light Horse
Potchefstroom Provincial Police
Pretoria Police
Prince Albert’s District Mounted Troops
Prince Alfred’s Volunteer Guard
Prince Albert’s District Mounted Troops
Prince of Wales’ Light Horse
Piquetberg District Mounted Troops
Queenstown Rifle Volunteers
The Rand Rifles
Richmond Town Guard
Rimington’s Guides
Railway Pioneer Regiment
Rhodesian Regiment
Roberts’ Horse
Scott’s Railway Guards
Scottish Horse, 1st and 2nd Regiment
Somerset East Town Guard
South African Constabulary
South African Light Horse
South African Mounted lrregular Forces
South Rhodesian Volunteers
Standerton Scouts
Steinaecker’s Horse
Stellenbosch Mounted Infantry
Stellenbosch Town Guard
Steytlerville Town Guard
Strathcoma’s Horse
Struben’s Scouts
Sutherland Town Guard
Tempest’s Scouts
Tarkastad Mounted Troops
Tarkastad Town Guard
Tembuland Mounted Rifle Corps
Thorneycroft’s Mounted Infantry
Touws River Town Guard
Transkei Mounted Rifles
Uitenhage Town Guard
Uitenhage Volunteer Rifles
Utrecht Vryheid Mounted Police
Veld Drift Town Guard
Vryburg Special Police
Walden’s Scouts
Warren’s Light Horse
Warren’s Mounted Infantry
Warren’s Scouts
Warrington Town Guard
Wedburg Town Guard
Wellington Town Guard
Western Province Mounted Rifles
Winterberg Mounted Rifles
Willowmore Town Guard
Warwick’s Horse
Young Husband’s Horse
Zeerust Town Guard
Zoutleif Town Guard
Indian Staff Corps
Natal Voluntary Veterinary Corps
Natal Voluntary Medical Corps
St John Ambulance Brigade
Imperial Hospital Corps