Thomas Jepson Gascoyne (or Thomas Jefferson Gascoyne, T. Jeb Gascoyne or Mills) (17 August 1876 – 4 October 1917) was an English professional cycling champion and world record holder who competed internationally on both bicycles and tandems.

He held world records for both 25 miles and the flying start quarter-mile. He held the English record for two miles on a tandem, and recorded an unpaced mile in 2 minutes 5 seconds.

According to the Otago Witness of 1907:

... it is questionable whether any rider, Fenn or MacFarland included, ever came up to the wonderful powers shown by Gascoyne.

... He is a living exception of the proved rule in cycle racing that he who paces must be left at the finish.

... From 1896 to 1901 he raced in various parts of the world, and his marvellous unpaced efforts never failed to send the crowds wild with excitement.

In the early 1900s he emigrated to Australia and did manual work before returning to cycle racing. He eventually settled in Preston, Victoria. He served in the Australian Army and died at the Battle of Passchendaele in World War I.