William Alexander Francis Balfour-Browne FRSE FZS FLS PRMS (1874–1967), known as Frank,^[1] was an English entomologist who specialised in Coleoptera, especially Dytiscidae (diving beetles).

Balfour-Browne was born at 16 Ebury Street in London to John Hutton Balfour-Browne KC (d.1921) and Caroline Lush.^[2]

He was educated at St Paul's School. As a child he was keenly interested in water beetles, and the group became the subject of his research throughout his life.^[1] He studied botany at Magdalen College, Oxford, and was then called to the bar in 1898. He returned to Oxford to study zoology the following year.^[3] Beginning in 1906 he taught biology at the Belfast College of the Royal University of Ireland (now known as Queen's University Belfast). In 1913 he became a lecturer in the University of Cambridge.

During the First World War he was a lieutenant in the Royal Army Medical Corps.^[2]

He was Professor of Entomology at Imperial College from 1925 to 1930 and was a friend of Robert Lloyd Praeger.

Balfour-Browne was the author of a Text-book of Practical Entomology, British Water Beetles published by the Ray Society, Concerning the Habits of Insects and many scientific papers, mainly on entomology.

Balfour-Browne was a Fellow of the Royal Entomological Society.

He died in Edinburgh on 28 September 1967.^[2]

He married in Glasgow on 4 October 1902 Elizabeth Lochhead Carslaw, daughter of Rev. Dr. Carslaw.^[2]

His son John Balfour-Browne was also an entomologist, who became a Principal Scientific Officer at the Natural History Museum, London.^[4]