It was a man named Captain Matthew Webb, who on 25th August 1875 set out from the Admiralty Pier, Dover and reached Calais in 21 hours and 45 minutes.
There have been many more people who have since swum across the Channel and in faster times, such as Enrique Tirabocci, from Argentina, who completed the swim on August 13, 1923 and finished it in a record time of 16 hours 33 minutes.
He was also the person to swim the route starting from the French side of the Channel.
However, the first woman to swim across the Channel was a Gertrude Ederle.
She began at Cap Gris Nez in France on August 6, 1926 and it took her 14 hours 30 minutes.