| 1870 | A first-winter shot at St. Leonards (ES) in early November. | WB dFH |
| 1913 | [An immature male shot at St. Leonards (ES) on 3 November.] | WB HR |
| 1914 | [An adult male shot at St. Leonards (ES) on 20 April (BoMNH 207535).] | WB HR |
| [An adult female shot at Pevensey (ES) on 26 April (BoMNH 207536).] | WB HR |
| 1948 | An adult seen on the sea to the west of Newhaven Harbour breakwater (ES) on 14 November (Alder, L.P. and James, C.M. 1950. Bonaparte's Gull in Sussex. British Birds 43:134-5.). | dFH (as 1949) |
| 1951 | A first-summer at Langney Point (ES) on 24 June (Harber, D.D. 1952. Bonaparte's Gull in Sussex. British Birds 45:333.). | * dFH |
| 1961 | [A first-summer recorded at Portobello, Brighton (ES) on 20 June was the 12th British record, but is no longer considered to be acceptable.] | */*94 ×/×94 dFH |