Robert McAndrew was born on March 22, 1802, in London, England.

He was a British merchant and ship-owner, naturalist, and collector of shells. Shortly after leaving school and his father's death in 1819, he joined his brother William Peter's fruit importing business of William McAndrew & Sons in London and Liverpool. Later, he concentrated on ship-owning through the business McAndrew & Co. in London. His interest in natural history, especially shells grew and in 1834, he joined the Literary and Philosophical Society of Liverpool. His many business trips to Spain, Portugal, and the Mediterranean led to his collecting of shells from the seashore. He was elected Fellow of the Linnean Society of London in 1847 and Fellow of the Royal Society in 1853. From 1856 to 1857 he was President of the Literary and Philosophical Society of Liverpool. McAndrew was elected Chairman of the newly formed General Dredging Committee (1858-1861). In 1867, he retired from his business interests. In 1872, together with Arturo Issel (1842–1922), he was awarded the Prix Savigny of the French Academy of Sciences for his work on Testaceous Mollusca of the Gulf of Suez. In 1873, he donated a bulk of his mollusk collection along with his library to Cambridge University Museum of Zoology. He also published numerous articles and reports on his research in various journals and magazines.

In 1829, he married Eliza McAndrew (1810–1892). He died on May 22, 1873, in London, England.