Humphrey Gainsborough (1718 – 23 August 1776) was an English non-conformist minister, engineer, and inventor.

Gainsborough designed Conway's Bridge, built in 1763 at Park Place close to Henley, an interesting rustic arched stone structure that still carries traffic on the road between Wargrave and Henley today.

In 1768, he improved the slope on the road up the steep White Hill to the east of Henley, straightening it in the process.

Watt had been working independently on improvements to the Newcomen "atmospheric engine" and subsequently patented these in 1769.

Philip Thicknesse wrote in The Gentleman's Magazine in 1785: … one of the most ingenious men that ever lived, and one of the best that ever died … Perhaps of all the mechanical geniuses this or any nation has produced.