Born into a poor and illiterate family in Glasgow, Lyon became an apprentice weaver at age nine. In adulthood, he moved to Kilmarnock, where he met and married Janet Thomson.

In the 1830s, he became involved with the Baptist church, but he left them and in March, 1844, he was baptised into the Church of Jesus Christ of the Latter Day Saints.

Amazingly for someone described as the best Mormon poet of the 19th century, Lyon only learnt to read in 1828, at the age of twenty five. By the 1840s, he had already worked for seven papers in Ayrshire, and assisted in the production of several poetry anthologies of other people's work.

As a convert he was atypical, and was described as a rather irreverent "Saul among the prophets".

He had over a dozen children, and was frequently visited in Kilmarnock by Mormon dignitaries who had travelled to Scotland. Amongst these were Levi Richards, Samuel W. Richards and Franklin D. Richards. And on one such visit, on 1st December, 1847, the Richards brothers travelled with Lyon to Robert Burns' birthplace in Alloway.

Lyons served a three year mission in Worcester, England, and later emigrated to Utah.

After his conversion to Mormonism, he found it difficult to find secular publishers. On the other hand, the LDS newspaper, the Millennial Star published copious amounts of work by what they described as "The Scottish Bard", starting on 15th November, 1845, when they published his poem Man. They would publish over forty more of his poems. Writing in January, 1849, Orson Spencer said to Orson Pratt that:

"Amongst the worth of contributors to the Star, I shall not be deemed invidious to name, distinctly and prominently, our highly esteemed brethren Elders Lyon and Mills. Their genius in the poetic department and the devotedness of their productions to the service of God and his people deserve the fostering care of all the Saints who love the high praise of God in sacred and commemorative songs. The excellent songs and hymns of our poets preach with unmistakable melody and power."

A hundred and five of his poems were collected in The Harp of Zion, which was published in a run of 5,148, and was the first complete book of poetry by a Mormon writer. These varied from devotional poems, to epics such as The Apostate, and also light hearted works in Lowland Scots such as Elegy on Wee Hughie, which was about an expired canary:

"But he'll ne'er wake us mair,

"For Hughie is deid"

Some of them were sung to such traditional Scottish tunes as The Lass o’ Glenshee. An example of his stronger and more vitriolic work is The Apostate

"I knew him, ere the roots of bitterness

"Had grown to putrid cancer in his soul.

"Then Revelation's light gleamed o'er his mind

"In strange fantastic dreams of future bliss,

"He saw the dawn, and this was quite enough

"For Speculation's visionary claim”

In the end, The Harp of Zion sold around 2,000 copies, and Lyon did not receive the profits from the work, since that was all donated to the Perpetual Emigrating Fund, which aimed to help converts migrate to the State of Deseret.

Lyon was a Mormon missionary between 1849-53, becoming conference president in Worcester in England. During this period he walked nearly five and a half thousand miles, baptised 360 people, and wrote 1000 letters. In 1849, he kept a missionary journal of his work.

After Worcester, he became a conference president in Glasgow.