| Honorific Prefix: | The Right Honourable |
| Sir John Thorold, Bt | |
| Honorific Suffix: | DL |
| Office: | Member of Parliament for Grantham |
| Term Start: | 1865 |
| Term End: | 1868 |
| Predecessor: | Frederick James Tollemache William Earle Welby |
| Alongside: | William Earle Welby, Edmund Turnor |
| Successor: | Frederick James Tollemache Sir Hugh Cholmeley, Bt |
| Birth Name: | John Henry Thorold |
| Residence: | Syston Park |
| Party: | Conservative |
| Parents: | Sir John Thorold, 11th Baronet |
| Children: | 5 |
Sir John Henry Thorold, 12th Baronet (9 March 1842 – 4 October 1922) was a British Conservative Party politician.
He was the eldest son of Sir John Thorold, 11th Baronet, and Elizabeth Frances Thoroton-Hildyard. Among his siblings were Montague George Thorold (who married the widow of the 6th Baron Rivers), Capt. Cecil Thorold of Boothby Hall, and Lt.-Col. Charles Cecil Hayford Thorold, who was killed in action during the Second Boer War.
His paternal grandparents were Sir John Thorold, 10th Baronet, and the former Mary Kent (a daughter of Sir Charles Kent, 1st Baronet). His maternal grandparents were Col. Thomas Blackborne Thoroton-Hildyard and the former Anne Catherine Whyte (niece and heiress of Sir Robert D'Arcy Hildyard, 4th Baronet). His maternal uncle was Thomas Thoroton-Hildyard, MP for South Nottinghamshire.[1]
Upon the death of his father in 1866, he succeeded to the baronetcy and the family estates, including Syston Park.
He was elected at the 1865 general election as a Member of Parliament for the borough of Grantham in Lincolnshire,[2] but did not stand again in 1868.[3]
He was appointed High Sheriff of Lincolnshire for 1876 to 1877, and was a Deputy Lieutenant of the county.
On 3 February 1869, Sir John married Hon. Alexandrina Henrietta Matilda Willoughby (1845–1931), daughter of Henry Willoughby, 8th Baron Middleton and the former Julia Louisa Bosville (a daughter of Alexander William Robert Bosville, granddaughter of the 3rd Baron Macdonald of Slate and descendant of Prince William Henry, Duke of Gloucester and Edinburgh). Together, they had five children:
Sir John died on 4 October 1922 and was succeeded in the baronetcy by his eldest son, John.[4]
Through his youngest son James, he was a grandfather of the Sir Anthony Henry Thorold, 15th Baronet, the Royal Navy officer who served as Captain of, was Commodore in Charge, Hong Kong, and served as High Sheriff of Lincolnshire.[4]
. F. W. S. Craig . British parliamentary election results 1832–1885 . 1977 . 2nd . 1989 . Parliamentary Research Services . Chichester . 0-900178-26-4 . 133.