Romney was born on July 13, 1806, in Dalton-in-Furness, Lancashire, England. He and his wife, Elizabeth, were converted to The Church of Jesus Christ of Latter-day Saints and baptized in the River Ribble in September 1837. As so many other British Saints did, they immigrated to the United States and arrived in Nauvoo, Illinois, on April 18, 1841. Miles helped with the construction of the Nauvoo Temple and was foreman of all woodwork.
After he and Elizabeth managed to save enough money to immigrate to Utah, they departed on March 18, 1850, by ox team and arrived on October 12. He became the Public Work Shop foreman and served from 1851 to 1856.
He served as a missionary in England from April 1856 until June 1858. In October 1860, the Romneys were called to help settle the St. George area. Consulting with Church architect William H. Folsom, he prepared the plans for the St. George Tabernacle. He also worked as master builder in charge of woodwork and built the circular staircases.
On October 12, 1874, Miles was working on the St. George Temple when he fell from a ladder breaking one of his arms and one of his legs. His injuries were very serious, but he recovered from this accident and resumed his activities on the temple and tabernacle. However, he died on May 3, 1877, in St. George from complications suffered from another fall while working on the St. George Temple.