John Robert Willis was born on February 14, 1825, in Philadelphia, Pennsylvania.

He was a teacher, naturalist, and first Nova Scotian conchologist. He moved to Halifax as a child and was educated at the National School. In 1846, he became its successful teacher and later principal. Willis was appointed superintendent of the new Industrial School in Halifax in 1864, and in 1865, he became secretary to the new Board of School Commissioners for the City of Halifax, a position he held until his retirement in 1875. He collected and classified shells, insects, and birds. In 1854, he exhibited his shells at the Nova Scotia Industrial Exhibition and won first prize. He sent exhibits of Mollusca and pearls to the Dublin Exhibition in 1864. He donated shell collections to local colleges, the British Museum, the Boston Society of Natural History, the Academy of Natural Sciences of Philadelphia, and the Smithsonian Institution. In recognition of his work, he was elected a corresponding member of the Liverpool Natural History and Microscopical Society in 1862, of the Boston Society of Natural History in 1863, and the Academy of Natural Sciences of Philadelphia in 1866. Willis was one of the founders of the Nova Scotian Institute of Natural Science in 1862 and worked for the establishment of a provincial museum.

In 1847, he married Mary Ann Artz (–1865) and in 1865, he remarried Eliza Jane Moseley (1846–1930). He died on March 31, 1876, in Halifax, Nova Scotia.