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

| Date_ | Constituency | c_u | Former_Incumbent | Winner | Cause_ |
|---|---|---|---|---|---|
| 27 December 1790 | Buckinghamshire | u* | William Wyndham Grenville | James Grenville | Elevated to the peerage |
| 27 December 1790 | Tavistock | u* | Charles William Wyndham | Lord John Russell | Chose to sit for Midhurst |
| 28 December 1790 | Monmouth | u | Marquess of Worcester | Charles Bragge | Chose to sit for Bristol |
| 28 December 1790 | Weobley | u* | Viscount Weymouth | Lord George Thynne | Chose to sit for Bath |
| 29 December 1790 | Buckingham | u | James Grenville | Sir Alexander Hood | Resignation to contest Buckinghamshire |
| 29 December 1790 | Petersfield | u | Lord North | Marquess of Titchfield | Resignation to contest Banbury |
| 31 December 1790 | Higham Ferrers | u | Viscount Duncannon | John Lee | Chose to sit for Knaresborough |