Euan Ironside Littlejohn was born on 26 October 1892 in Nelson, New Zealand where his father William Still Littlejohn had been assistant master at Nelson College since his arrival from Scotland in 1881. Euan's mother Jean Littlejohn (nee Berry), a teacher, met her husband-to-be whilst both attended the University of Aberdeen, evenutally following William to NZ where they married in Wellington on Christmas Day 1885. William became Principal of Nelson College in 1898, then took up headmastership at Scotch College, East Melbourne in 1904. Euan had an elder brother Charles (enlisted for WWI in the UK), and three sisters. He commenced his schooling at Nelson College in 1901 before moving to Scotch College in 1904. The family resided the Scotch College Principal's Residence, Landsdowne Street, East Melbourne until the move to the Hawthorn campus in during the 1920's.

Euan was active with the Shooting Team, being Captain in 1910 and 1911, and also a member of the First VIII in 1911. He was a prefect in 1909,1910 and 1911 and winner of the Exhibition in Biology and Natural Philosophy (Physics) in 1911. At school, Euan was a cadet for 7 years and Subaltern for 2 years. In 1912 he entered Ormond College to study Medicine, rowing in the Melbourne University crew during 1913 and 1914. With a year to go to complete his Medical degree, Euan enlisted in the AIF Medical Corps as a Private on 10 November, 1914, embarking from Adelaide 10 days later on the HMAT Kyarra, disembarking at Alexandria where he joined the No.1 Australian General Hospital located at Heliopolis near Cairo. Early June 1915, he returned to Melbourne on the HMAT Ceramic to complete his medical course, graduating with an MB.BS in 1916.

Re-enlisting on 29 November, 1916, Euan was appointed Captain in the A.A.M.C, and embarked on the HMAT Berrima on 16 December, 1916 . On arrival in the UK early February, 1917, he spent a month at the A.A.M.C Training Deport before moving to the SMO Hurdcott Depot #2 at Camp Parkhouse. On 1 August, 1917 he proceeded to France to join the 3rd Australian Casualty Clearing Station at Brandhock, near Ypres. He was granted a month's leave to the UK early February 1918,during which time he married Mary Andrews (from Australia) in Kensington on 11 February, 1918. After rejoining his unit in early March 1917 , he was detached to the RAMC School of Instruction for a week. Euan remained with the 3rd ACCS until after Armistice, returning to the UK on March 1919. He took 6 months leave to work at the Royal Southern Hospital in Liverpool. During this time he was mentioned in despatches. He remained on leave until mid December, when he returned with his wife Mary to Australia on the HMAT Mantua.

Euan and Mary had two sons, Willian Euan Ironside born in 1920, and Gordon Brefny born in 1923. Upon his return Euan set about establishing a General Practice in Heidelberg Road, Ivanhoe with his brother Charles where he practised for over 40 years. In 1928 Euan received his M.D (Doctor of Medicine). In 1927 he became assistant to Frank Coles as Scotch's Medical Officer, taking over from Frank in 1934. His first  'appointment' each day was always Scotch College. Euan's son William, also a doctor, took on this role when his father retired in 1965. During the 1930's Euan returned to coach the rowing team at Scotch College. Both sons enlisted for WW2. William became a Lieutenant in the Royal Australian Navy and was awarded a D.S.C for bravery and skills, presented by King George VI at Buckingingham Palace on 21 March, 1944. Gordon joined the 12th Squadron, Royal Air Force and was killed on 7 September, 1942 during a flying battle over Germany. Euan passed away in 1968, aged 75 years, at his home in Hawthorn where he had resided for over 30 years.