Born in Kempsey and educated in Tamworth, NSW, Commodore Jason Sears, RAN joined the Navy in 1986 as part of the first entry into the Australian Defence Force Academy. He graduated in 1988 and was awarded an Honours Degree and The University Medal in History in 1989. Following his specialist supply training in 1990, he joined HMAS Torrens and then HMAS Adelaide (II) as Deputy Supply Officer. From 1992-94 CDRE Sears served as Research Officer to the Chief of Navy in Canberra before undertaking fulltime PhD studies at University of NSW. He was awarded his Doctorate in History in 1998. 

From 1997-99 CDRE Sears was the Materiel Support Manager at HMAS Cairns before joining the newly built Anzac Class frigate, HMAS Arunta, in Victoria as Supply Officer. He home-ported the ship to WA and participated in RIMPAC exercises off Hawaii in 2000 and a NorthEast Asian deployment to commemorate the 50th Anniversary of the Korean War in 2001. In October 2001 CDRE Sears was posted to the Defence Materiel Organisation where he worked as Sustainment Manager for the ANZAC frigates. In November 2003 CDRE Sears and his family moved to Washington DC, USA, where he served on the Naval Attaché staff as Staff Officer Supply and Training.

CDRE Sears returned to Australia in October 2005 to take up the position of Sustainment Manager at the Mine Warfare and Clearance Diving program office based at HMAS Waterhen. He was responsible for the logistic support of the Navy's clearance diving teams, hyperbaric facilities, six Mine Hunter Coastal (MHC) vessels and two Minesweeping vessels. In 2009 CDRE Sears returned to sea as Supply Officer of the amphibious ship, HMAS Kanimbla, which deployed in support of Operation PADANG ASSIST to provide disaster relief to earthquake victims in Sumatra.

From December 2009 until January 2012, CDRE Sears commanded the Navy's Centre of Excellence for mine warfare, HMAS Waterhen. In 2012 he joined the Australian Fleet Sea Training Group as the Fleet Supply Officer.  

CDRE Sears was promoted to CAPT on 1 January 2013 and posted as Director Strategic Logistic Development in the Joint Logistic Command in Canberra. He served in that role for ten months before an appointment as Director International Logistics in October 2013. In this role he was also Chair of the 18 nation United Nations working group that produced a Military Unit Manual for Logistics. CDRE Sears took up his appointments as Australia’s first resident Defence Adviser to Sri Lanka on 19 January 2015 and inaugural Defence Adviser to Bangladesh on 25 March 2015.  

He returned to Australia in January 2018 as the Director of the Guided Missile Frigate (FFG) System Program Office at Garden Island, Sydney, later taking up the position of Director Amphibious Combat and Sealift SPO in December 2019. 

Following his promotion to the rank of Commodore in December 2022, CDRE Sears took up the role of Director General Maritime Support Branch and Senior ADF Officer Defence Plaza Sydney. In March 2025 CDRE Sears was posted back to Garden Island, Sydney as Director General Major Surface Ships which partners with Navy and Industry to deliver seaworthy warships for our nation.

CDRE Sears has two sons, Alexander and William, who are studying at university. His interests include football, swimming, tennis and gardening.