| Honorific-Prefix: | The Right Honourable |
| The Lord Sandhurst | |
| Honorific-Suffix: | KC |
| Office1: | Member of the House of Lords |
| Status1: | Lord Temporal |
| Term Label1: | as an elected hereditary peer |
| Term Start1: | 23 June 2021 |
| 1Blankname1: | By-election |
| 1Namedata1: | 23 June 2021 |
| Predecessor1: | The 4th Earl of Selborne |
| Birth Name: | Guy Rhys John Mansfield |
| Birth Date: | 3 March 1949 |
| Party: | Conservative |
| Parents: | John Mansfield, 5th Baron Sandhurst |
| Occupation: | Barrister |
| Awards: | Took silk |
Guy Rhys John Mansfield, 6th Baron Sandhurst, (born 3 March 1949), is a British barrister, hereditary peer and Conservative member of the House of Lords.
He served as Chairman of the General Council of the Bar in 2005.[1] He is the current Chairman of Research for the Society of Conservative Lawyers.[2]
Lord Sandhurst was elected as a member of the House of Lords on 17 June 2021 in a Conservative hereditary peers' by-election.[3] He took office on 23 June 2021.[4] He made his maiden speech on 14 September 2021 during the Crime, Police & Sentencing Bill.