Robert McNair Ferguson FRSE FRSSA (1829–1912) was a Scottish mathematician and a founder of the Edinburgh Mathematical Society.

He was born on 8 July 1829, the son of John Ferguson, a pawnbroker, and his wife, Elisabeth Cochran.

[1] From 1858 till his retirement in 1898 he was headmaster in the Edinburgh Institute (now known as Stewart's Melville College), where he taught among others William Cunningham.

He was founding member of the Edinburgh Mathematical Society in 1883 and was elected his president in 1885–1886.

He is buried in the south-east section of Grange Cemetery in south Edinburgh.