Turning his interests abroad, Trevithick also worked as a mining consultant in Peru and later explored parts of Costa Rica. Throughout his professional career, he went through many ups and downs, and at one point faced financial ruin, also suffering from the strong rivalry of many mining and steam engineers of the day. During the prime of his career, he was a well-respected and known figure in mining and engineering, but near the end of his life he fell out of the public eye.
Richard Trevithick was born at Tregajorran (in the parish of Illogan), between Camborne and Redruth, in the heart of one of the rich mineral-mining areas of Cornwall. He was the youngest-but-one child and the only boy in a family of six children. He was very tall for the era at 6 ft 2in, as well as athletic and concentrated more on sport than schoolwork. Sent to the village school at Camborne, he did not take much advantage of the education provided; one of his school masters described him as "a disobedient, slow, obstinate, spoiled boy, frequently absent and very inattentive". An exception was arithmetic, for which he had an aptitude, though arriving at the correct answers by unconventional means.
Trevithick was the son of mine "captain" Richard Trevithick (1735–1797) and of miner's daughter Ann Teague (died 1810). As a child he would watch steam engines pump water from the deep tin and copper mines in Cornwall. For a time he was a neighbour of William Murdoch, the steam carriage pioneer, and would have been influenced by his experiments with steam-powered road locomotion.
Trevithick first went to work at the age of 19 at the East Stray Park Mine. He was enthusiastic and quickly gained the status of a consultant, unusual for such a young person. He was popular with the miners because of the respect they had for his father.
In 1797, Trevithick married Jane Harvey of Hayle. They raised six children: