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.