Captains of HMS UNICORN
| 1 Jan. | 1874 | Commander Harry W. Brent |
| (from HMS BRILLIANT) | ||
| 9 April | 1874 | Commander Wm. E.S. Brome |
| 9 April | 1877 | Commander Herbert Dolphin |
| 13 Oct. | 1879 | Commander Orford S. Cameron |
| 18 Oct. | 1882 | Commander P. Walker |
| 16 April | 1885 | Commander Wm. N.G. Nowell |
| 18 Oct | 1888 | Lieutenant & Commander Francis A. Brookes |
| 1 Aug. | 1891 | Lieutenant & Commander Wm. F.G. Clarke |
| 1 July | 1897 | Lieutenant & Commander Wm. L. Down |
| 9 Nov. | 1898 | Lieutenant & Commander Ernest L. Austen |
| 1 Jan. | 1904 | Lieutenant Samuel M. Agnew |
| 1906 | Lieutenant H.S. Glenny, RNVR | |
| 1912 | Lieutenant Commander R. Still, RNVR | |
| 1919 | Captain W.M. Smail, VD*, RNVR | |
| 1927 | Captain W.F. Keay, OBE, VD*, DL, ADC, RNVR | |
| 1945 | Captain D.R. Miller, OBE, VRD*, ADC, RNVR | |
| 1954 | Captain J.C.L. Anderson, VRD*, ADC, RNVR | |
| 1959 | Captain P. Sime, VRD*, RNR | |
| 1963 | Captain T.A.C. Keay, VRD**, RNR | |
| 1966 | Captain W.R. Stewart, OBE, VRD*, RNR |

