Edwin Octavius Tregelles (19 October 1806 – 16 September 1886) was an English ironmaster, civil engineer and Quaker minister.
He was the youngest of the seventeen children of Samuel Tregelles (1766 –1831) and his wife, Rebecca Smith (1766–1811) of Falmouth, Cornwall, United Kingdom.
Edwin Tregelles's father had formed an Iron Founding partnership with his Quaker relatives in Falmouth, the Foxes and in South Wales, the Prices.
Edwin was apprenticed to Joseph Tregelles Price (1784–1854) the manager of the Welsh wing of the firm, at the Neath Abbey Iron Works.
He went into business as a civil engineer, superintended the introduction of gas lighting to towns in southern England.