[1] The unit recruited primarily from New South Wales, and had detachments in Murrumburrah, Gunnedah, Gundagai, Quirinidi, Mudgee, and various other NSW towns.

[2] When the Second Boer War began in late 1899, New South Wales raised multiple contingents which included detachments from the regiment.

The first contingent left Newcastle on 14 November 1899 for Cape Town, South Africa, arriving on 13 December, with a second contingent leaving Sydney on 17 January 1900, arriving 23 February.. Two detachments of the regiment served under General John French's Cavalry Division during the Second Boer War in 1899, composed of 141 men and 157 horses.

[2][3] The unit then participated in the Battle of Poplar Grove and took part in occupying the towns of Driefontein and Bloemfontein.

They also saw action in the Battle of Belfast in 1901, where General Kitchener commended the 1st Australian Horse for its "gallant conduct"; later withdrawing from South Africa by late March of the same year, arriving back in Sydney on 2 May on board the transport ship Tongariro.