Sir Harold Jeffreys, FRS (22 April 1891 – 18 March 1989) was a British mathematician, statistician, geophysicist, and astronomer. His book, Theory of Probability, which first appeared in 1939, played an important role in the revival of the objective Bayesian view of probability.

Harold Dixon may refer to:

Harold Parker State Forest is a publicly owned forest with recreational features encompassing more than 3,300 acres (1,300 ha) in the towns of Andover, North Andover, North Reading, and Middleton, Massachusetts. Ponds, swamps, rolling hills, glacial erratics and rocky outcroppings can be found in the state forest, which features more than 35 miles (56 km) of backwoods roads and trails as well as remnants of 18th-century farming and milling operations. It is managed by the Massachusetts Department of Conservation and Recreation.