Onno Eichelsheim (Schiedam, 1966) began his military career as a cadet at the Royal Netherlands Military Academy in Breda in 1986. In 1990, he completed his basic flight training and was awarded his helicopter pilot wings. Until 1996, he served in a variety of operational positions as helicopter pilot with 299 Squadron at Deelen Air Base, during which time he was deployed to Bosnia. Back in the Netherlands, Onno Eichelsheim was assigned as flight commander of 301 Apache Squadron, and in 2000 was again deployed to Bosnia. In 2004, he was deployed to Kabul (Afghanistan) and in 2006 he completed a tour of duty in Uruzgan (Afghanistan). 

In April 2016, Onno Eichelsheim was promoted to the rank of major general and appointed director of the Netherlands Defence Intelligence and Security Service (NLD DISS). 

In July 2019, Eichelsheim became Vice Chief of Defence in the rank of lieutenant general. In this capacity, he was also a member of the Cyber Security Council. 

He was promoted to general on 1 April 2021 in preparition for his new appointment as Chief of Defence. On 15 April, as the new Chief of Defence, General Eichelsheim became the highest ranking member of the Netherlands armed forces.