James Parkin joined the Royal Navy as a Warfare Officer in 1997 and graduated from BRNC Dartmouth in 1999. He has served in numerous warships and shore establishments of every size, including HMS Berkeley, HMS Manchester, and HMS Somerset, and has commanded the Patrol Vessel HMS Ranger, the Type 23 frigate HMS Montrose, the Fleet Amphibious Flagship HMS Bulwark, and (since 2018) the UK Amphibious Task Group. 

He has deployed worldwide, including a tour in Baghdad, and worked in both the Ministry of Defence in London and Navy Command Headquarters on Whale Island. He is currently based at Royal Marines Stonehouse as COMATG. 

As well as being the senior serving Trustee of the Royal Navy and Royal Marines Charity, James is a Younger Brother of Trinity House, a Liveryman of both the Worshipful Company of Distillers and the Worshipful Company of Coachmakers, a Freeman of the Worshipful Company of Shipwrights, and an Associate Fellow of the Nautical Institute. He is a member of the RNRMC's Financial Risk and Audit Committee.