Trelawney William Saunders was born on April 16, 1821, in Plymouth, Devon, England.

He was a geographer. In 1839, he came to London to join the famous publishing house of Samuel Bagster & Sons. In 1846, he became a member of the Royal Geographical Society. He began to sell maps and became the first map-seller in London to publish a classified catalogue of the best foreign and English publications. In 1851, he produced a weather chart of the British Isles and the neighbouring coasts and posted it daily at the Great Exhibition in Hyde Park. In 1854, he began to work for the Royal Geographical Society. He classified and arranged the books and maps, acting temporarily as a librarian, and until 1857, filling the office of map curator. He organized and managed the geographical department of Mr. Edward Stanford's business. He edited a series of library maps, produced the series of school wall maps, and designed and oversaw the construction of a detailed survey of London. In 1868, he began to work as a Geographical Assistant to the India Office, a position he held until his retirement in 1885. He organized an extensive collection of maps, plans, charts, and memoirs and published his famous Sketch of the Mountains and Rivers of India (1870) and An Introduction to the Survey of Western Palestine (1881). He was elected a Fellow of the Royal Geographical Society.

In 1844, he married Catherine Ann Knight (1818–1882). He died on July 22, 1910, in Newton Abbot, Devonshire, England.