Simon Evans was born at Tynyfedu, in mid-Wales, not far from Lake Vyrnwy, a reservoir supplying water to Liverpool. His father, Ellis Evans, was a farmer, but the family farm was too poor to support a growing number of sons, so Ellis and his family left Wales for Merseyside in about 1907. Here Simon, tall for his age, and speaking with a strong Welsh accent, did not have an easy time at school, but did owe his love of literature to an influential teacher. When he left school, he worked for the General Post Office as a messenger boy and postman.

On the outbreak of the First World War, Evans joined the 16th Battalion of the Cheshire Regiment, and spent much of the next five years in trench warfare, an experience which left him mentally and physically scarred. He was wounded and invalided back to England at least once, and finally wounded and gassed in 1918. The misery and carnage he witnessed caused him to question his Christian faith, and he parted company with the church because the church would not withdraw its support for the armed services after the war had ended. Although it affected him to the end of his life, he rarely spoke or wrote of his time in the army.

Evans returned to Merseyside after an operation on his wounded legs, but found himself unable to settle down to the life of an urban postman. Gas damage to his lungs meant he still had to spent time in convalescent homes, and on one occasion was advised to take a walking holiday before returning to his work as a postman. This holiday he took in or near Cleobury Mortimer, and there he found a postman willing to exchange a rural postal round for Simon's urban one. With some difficulty, an exchange was arranged, and Evans took up work in Cleobury Mortimer in 1926.

His new life in Cleobury Mortimer suited him perfectly. He took lodgings in Lower Street, joined the Bowling Club and lived a carefree bachelor life, with a growing number of friends. He was later to claim that as a country postman he knew many more people than he had known when working in a town. At the time, the GPO provided rural walking postmen with shelter huts at the further point of their rounds, and Evans took full advantage of his, turning it into a place where he could read, write, and even spend the nights when off duty. In 1928, he won a scholarship offered by the Union of Post Office Workers to enroll on a correspondence course in English at Ruskin College, Oxford. This was to prove a turning point in his career, as it opened the door to literature, and led to his becoming a publisher writer and a broadcaster.

Starting as a writer of short articles, largely about rural life as experienced by a country postman, Evans soon caught the attention of the BBC and became a regular contributor to programmes on the Midland Service. His broadcasts were heard by Shannie, the daughter of Heath Cranton who suggested to her father that Evans' work would be worth publishing in book form. A meeting between Cranton, Evans, and the Rev Father Rope (one of Cranton's existing authors) was arranged, and this resulted in the publication of Evans' first book on 20 March 1931. This was a collection of short items, most of which had already appeared in print or on the air. It was followed by his second book the following year, and three more in the next few years. His first book, Round About the Crooked Steeple, was the most successful, and the only one to be reprinted, the first reprint being dated 9 April 1931, only 20 days after the first impression. Throughout the 1930s, not only did Evans continue to work as a postman, but he also continued to write for periodicals, mostly local, but also occasionally for national weekly magazines and even daily newspapers. He often re-wrote or re-worked earlier pieces, and re-submitted these for publication elsewhere. A particular idea or anecdote, therefore, might appear in several publications, might also be broadcast on the BBC, and finally end up in one of his books. Four of his books were largely collections of articles which had already been published and broadcast pieces, but one, Applegarth, was a full-length novel, and one which was so constructed as to admit of a sequel, should the opportunity arise.

Although sometimes referred to as a poet, Evans wrote little poetry, though frequently quoted poems by others in his books. His biographer, Mark Baldwin, argues that Evans was more of a craftsman than an imaginative writer. Much of his work was inspired by his own experiences, rather than by his imagination, and this placed something of a limit on the range of his output, as he was reluctant to look back to his war-time experiences too frequently. Little of his writing refers to the war, although one powerful poem 'Memories', does describe how he shot a young Prussian soldier, and was very moved by finding round his neck a locket containing a woman's portrait - 'In distant homes are broken hearts, because we puppets play our parts.'As he had little experience of the world apart from the war, life in Wales, and life on Merseyside, it was necessarily his life and encounters as a rural postman which provided most of the raw material for his writing, as well as the basic setting for his one novel, Applegarth. However, on this more homely ground his tread is sure. His evocation of country life is enjoyable. He captures well the wit and wisdom of farmer and shopkeeper, publican and poacher, and he tells a good tale, holding his reader's interest. To read Evans is to be inspired, to long for the winding lane, the rolling hillside, the buffeting of the wind, a glimpse of pheasant, heron or rabbit, and good company at a pub fireside at the end of the day.

His frequent visits to the BBC studio in Birmingham brought Evans into contact with a professional singer and entertainer, Doris Aldridge, who was working at the time in children's radio as 'Aunty Doris'. They were married in 1938, and lived in a house in Cleobury Mortimer, built to their own design. Less than two years later, Evans was badly affected by his recurring lung trouble in the severe winter weather of 1939/40, and died in hospital in Birmingham on 9 August 1940, a day short of his 45th birthday. There were no children of the marriage, and his widow soon left Cleobury Mortimer to pursue her professional career. She never remarried, and died in 2006.