The grandson of a Yorkshireman, Fearnley was born in Norway and had his early artistic training there, and in Denmark. He was much influenced by his fellow Norwegian, Johan Christian Dahl (1788-1856), with whom he worked in 1829 and 1830. Like Dahl, Fearnley's paintings alternate between oil sketches and larger, composed landscapes meant for exhibition. Dahl urged him to specialise in the Norwegian scenery, but Fearnley travelled and sketched widely in Europe, including Italy where he spent three years beginning in 1832. He died in 1842, at the age of 39, after contracting typhus.