Harry Clasper (5 July 1812 – 12 July 1870) was a professional rower and boat builder from the Tyneside in England. He was an innovative boat designer who pioneered the development of the racing shell and the use of outriggers. He is said to have invented spoon-shaped oars.
He was the first of three well-known Tyneside oarsmen, the other two being Robert Chambers and James Renforth.
Harry Clasper was born in Dunston, now part of the Metropolitan Borough of Gateshead, but then an independent village on the south bank of the River Tyne, a mile upriver from Gateshead. Later his family moved to Jarrow, also on the south bank on the Tyne, downriver from Newcastle. At the age of 15, he began to work at Jarrow Pit, which was notorious for firedamp. After a while Clasper decided that mining did not suit him and he became apprenticed as a ship's carpenter in Brown's Boatyard, Jarrow. There he learnt about woodworking and the principles of boatbuilding. This would be useful to him in later life.
After a while his family moved back to Dunston and Clasper became employed as a coke burner and wherryman for the Garesfield Coke Company at nearby Derwenthaugh. His work as a wherryman would also serve him well in later life. Clasper then worked for a while at Hawks, Crawshay and Sons Ironworks around the mid-1830s.
In 1836 he married his cousin Susannah Hawks, a member of a wealthy family. Their wedding certificate shows Clasper signing with a cross, as he could not read or write, whilst Susannah signed her name.
Clasper formed a racing crew with his brother William and two other men. Harry rowed as stroke (the oarsman who sits nearest the stern, opposite the cox and who sets the stroke rate) and another brother, Robert, acted as cox. The boat was named "Swalwell". The crew started well, winning several races and became known as the Derwenthaugh crew.