Ralph Lent Jeffery (3 October 1889 Overton, Yarmouth County, Nova Scotia, Canada – 1975 Wolfville, Nova Scotia) was a Canadian mathematician working on analysis.
Jeffery Hall at Queen's was named for him.
In 1937 he was elected a Fellow of the Royal Society of Canada.
In 1925 Jeffery exhibited a bounded function of two real variables, continuous in each, yet fails to have an integral.
In 1951 Jeffery published Theory of Functions of a Real Variable which was noted for its coverage of integration theory.