List of Great Britain by-elections (1790–1800) By-elections 17th Parliament (1790–1796)

| Date_ | Constituency | c_u | Former_Incumbent | Winner | Cause_ |
|---|---|---|---|---|---|
| 27 April 1791 | Harwich | u | Thomas Orde | Thomas Orde | Governor of the Isle of Wight |
| 28 April 1791 | Ludgershall | c | George Augustus Selwyn | Samuel Smith | Death |
| 29 April 1791 | Petersfield | u | Marquess of Titchfield | Welbore Ellis | Resignation to contest Buckinghamshire |
| 2 May 1791 | Minehead | u | Viscount Parker | Viscount Parker | Comptroller of the Household |
| 4 May 1791 | Stirling Burghs | c* | Sir Archibald Campbell | Andrew James Cochrane | Death |
| 6 May 1791 | Dorset | u* | William Morton Pitt | William Morton Pitt | Seeks re-election due to holding contract to supply cordage |
| 12 May 1791 | Lymington | u | Harry Burrard | Nathaniel Brassey Halhed | Resignation (Riding Forester of the New Forest) |
| 18 May 1791 | Appleby | u | Richard Ford | John Theophilus Rawdon | Resignation |