Troughton & Simms was a British instrument-making firm, formed when Edward Troughton in his old age took on William Simms as a partner in 1826.
It became a limited company in 1915 and in 1922 it merged with T. Cooke & Sons to form Cooke, Troughton & Simms.
The firm produced hundreds of astronomical instruments such as mural circles, transit circles, sextants, and other astronomical instruments for observatories around the world.
Previously, Troughton had been a sole proprietor, and before that he was in partnership with his brother John. John died and Edward took on Simms in 1826. Edward Troughton died in 1835.