The 32-year-old from Orpington, Kent, completed an 87-mile run from Marble Arch to Dover, followed by a 21 mile swim across the English Channel, and a 181-mile bike ride from Calais to the Arc de Triomphe in Paris.
He also became only the fifth competitor ever to complete the feat without wearing a wetsuit for the Channel swim section,
After setting off at 5pm on August 2, Mr Leek arrived in the French capital on Tuesday.