1810-1860. Fifth son of Admiral Sir Thomas and Betsy [Wynne] Fremantle (see family tree).
- Attended Royal Naval College, Portsmouth
- Served as midshipman with Captain Lord Adolphus Fitzclarence in the Challenger and Pallas
- 1829: Promoted Lieutenant
- 1842: Promoted Captain
- Private secretary to his brother, Thomas Fremantle, when Secretary at war and Chief Secretary for Ireland
- 1847: Appointed to Raleigh
- 1853: Appointed to Juno. Took possession of Kuria Muria.
- 1858: Juno's commission, mostly in the Pacific attached to the Australian station, ends with half his officers under arrest.
After returning to England, Stephen was unemployed and died two years later.