His Cornish grandfather Pascoe Grenfell was a tin and copper manager and Member of Parliament (MP), while his father, Charles Pascoe Grenfell, was a director of the Bank of England from 1830 to 1864. His maternal grandfather was William Philip Molyneux, 2nd Earl of Sefton.
Grenfell was elected as a Liberal Member of Parliament for Stoke-upon-Trent at a by-election in September 1862, and was re-elected at the general election in 1865. At the general election three years later, in 1868, he stood in the Liberal interest for South West Lancashire, but was defeated. He came forward again at the general election of 1880, standing for Barnstaple, but was again defeated.
He was a leading member of the Bimetallic League, and Governor of the Bank of England between 1881 and 1883 following a period as its Deputy Governor. He was also a member of the Council of the Corporation of Foreign Bondholders and was on the boards of several insurance companies.
- Leigh Rayment's Historical List of MPs – Constituencies beginning with "S" (part 5)
- "Obituaries - Mr. Henry Riversdale Grenfell". The Times (36871). London. 12 September 1902. p. 7.
- "Governors of the Bank of England" (PDF). Bank of England. Archived from the original (PDF) on 12 February 2012. Retrieved 3 January 2014.
- "Deputy Governors of the Bank of England" (PDF). Bank of England. Retrieved 3 January 2014.[permanent dead link]
- Hansard 1803–2005: contributions in Parliament by Henry Grenfell
- Lundy, Darryl. "Henry Riversdale Grenfell". The Peerage.