| Honorific-Prefix: | The Most Honourable |
| The Marquess of Abergavenny | |
| Birth Date: | 15 July 1883 |
| Parents: | Lord George Montacute Nevill Florence Mary Soanes |
| Spouse: | Isabel Nellie Larnach |
| Issue: | Angela Isabel Nellie Nevill John Henry Guy Nevill Lord Rupert Nevill |
| Tenure: | 10 January 1938 – 30 March 1954 |
| Other Titles: | 8th Earl of Abergavenny 4th Earl of Lewes 8th Viscount Nevill |
| Marquess of Abergavenny | |
| Successor: | John Nevill, 5th Marquess of Abergavenny |
| Residence: | Eridge Park |
Major Guy Temple Montacute Larnach-Nevill, 4th Marquess of Abergavenny, JP, DL (15 July 1883 – 30 March 1954)[1] was a British peer.
Guy was the eldest son of Lord George Montacute Nevill and his wife Florence Mary Soanes.
He married Isabel Nellie Larnach (d. 5 November 1953), the only child of James Walker Larnach, on 30 October 1909, and had three children:
After the death of his father-in-law, he changed his surname (for himself and his wife only) from Nevill to Larnach-Nevill by deed poll on 17 June 1919. He gained the rank of captain in the Scots Guards and gained the rank of honorary major in 1920 in the Sussex Yeomanry. He held the office of Deputy Lieutenant and also held the office of Justice of the Peace for Sussex.[3] Larnach-Nevill succeeded to the marquessate in 1938 on the death of his uncle, Henry Nevill, 3rd Marquess of Abergavenny, who died with no surviving male issue. The 4th Marquess died in 1954 and was succeeded by his elder son, John.
His daughter Lady Angela Isabel married Digby Pepys, 7th Earl of Cottenham.[4]