Roy was the son of Joseph and Ellen Longhurst and he had one sister, Mariel. In the 1901 census, the Longhurst's also had two servants, Kate Millington and Edith Wheater.
Roy was educated at the Royal Grammar School in Jesmond, Newcastle upon Tyne. He married Mary Robina Burns in Spring, 1915. They lived at 11 Queens Gardens, Benton, Newcastle upon Tyne.
Roy was commissioned from the University Officers' Training Corps a few months after he joined in August 1914 into the Northumberland Fusiliers, 23rd Battalion. He was promoted to Captain while undergoing preliminary training at Alnwick, and went to the Western Front in January 1916. He was engaged in the heavy fighting at Arras, Albert, and La Boisselle. He was gazetted Major on the field, and subsequently Acting Lieutenant-Colonel. He was mentioned in Field Marshal Sir Douglas Haig's despatch of 13th November, 1916, and during his Colonel's illness was personally complimented again by Sir Douglas for his work.
In October 1917, he was granted six months' leave of absence in England and appointed Commandant of the Training School for the Durham Auxiliary Volunteer Forces, being attached to the Northumberland Fusiliers, 3rd Battalion. On Friday 8th March 1918, while on military service at home, Roy was accidentally killed when he crashed his motorcycle into a tram car on the Benton Road, Newcastle upon Tyne, during a snowstorm at around 1.25pm. He was taken for treatment to the 1st Northern General Hospital, which was based on the premises of Armstrong College. He died from his injuries a week later on 15th March 1918 only weeks before his thirtieth birthday.