Major Denis Dissanayaka is from the Regiment of Sri Lanka Armoured Corps. He received his primary education from Ashoka English Medium School Horana and secondary education from Royal College Colombo. He joined the Sri Lanka Army on 17 September 2012 under Intake 30 to the General Sir John Kotelawala Defence University (KDU). After completion of the basic military training at SLMA, he was commissioned to the rank of Second Lieutenant on 20 December 2015 and posted to the Regiment of Sri Lanka Armoured Corps and subsequently posted to 3rd Armoured Regiment.
During his tour of duty, he has held the following appointments:
Command Appointments
- Troop Leader - 3rd Armoured Regiment
- Officer Commander - 5th Reconnaissance Regiment
Staff Appointments
- Assistant Adjutant – 3rd Armoured Regiment
- Adjutant – 6th (Rft) Regiment
- SO 3 Records – MS Branch
Instructor Appointments
- Troop Commander – Kotelawala Defence University.
In recognition of his valuable and unblemished service rendered to the Army/ Country, he has been awarded with the following medals:
- 75th Anniversary of Independence Medal
- Sri Lanka Armed Services Long Service Medal
- Sewabhimani Medal
- Service Medal