Initially educated at Penarth Boarding School, he moved to Australia with his family in 1911, with his father acquiring a property near at Koorlong, near Mildura, Victoria.

[1] Pearse served in the Militia for two years with the 73rd Infantry Regiment, before volunteering for overseas service with the Australian Imperial Force (AIF) during the First World War.

He sailed from Melbourne on 10 September 1915 aboard the Star of Victoria,[3] assigned to the 9th Reinforcement for the 7th Battalion reaching Gallipoli shortly before the evacuation and spending two weeks in the line there in December 1915.

[4] After transferring to the 2nd Machine Gun Company, assigned to support the 2nd Brigade, Pearse subsequently saw action on the Western Front where he was wounded on 24 August 1916 but soon returned to his unit.

[2] On 28 September 1917 he was awarded the Military Medal for an action in single-handedly raiding a German machine gun-post east of Ypres in Belgium: Normally this man is a runner ....and throughout he showed an utter disregard of danger in carrying messages, guiding parties and in bringing in wounded men on every return run.

Challinger also references Pearse's army record which quite apart from his awards for valour includes entries for neglect of duty, absence from guard and disobedience to orders.

His magnificent bravery and utter disregard for personal danger won for him the admiration of all troops.Samuel Pearse was buried in a military graveyard near the Obozerskaya railway station, between Emtsa and Archangel, North Russia.

[10][14] While on leave in England in January 1918 Pearse met Kitty Knox, an ambulance driver serving in the Women's Army Auxiliary Corps.