Osbourne Reynolds (born August 23, 1842 - February 21, 1912) was an engineer and physicist known for his work in hydraulics and hydrodynamics.

Reynolds was born in Belfast in Ireland and died in Watchet[?] in Somerset.

Some biographical data:

• 1867 graduated for Queens' College Cambridge[?]
• 1868 became first professor of engineering in Owens College, Manchester[?]
• 1877 elected a fellow of the Royal Society
• 1888 elected a Royal Medallist[?]

The Reynolds number is named after him.