Longest journey by motorcycle (individual)
Who
Emillio Scotto
What
735000 kilometre(s)
Where
Argentina (Buenos Aires)
When
Age Restriction: Applications for this record title will only be accepted if the applicant is 16 years of age or over.

Emilio Scotto of Buenos Aires, Argentina completed the longest ever journey by a motorcycle, covering over 735,000 km (457,000 miles) and 214 countries and territories, from 17 January 1985 to 2 April 1995.

This is classed as a single journey because he didn't return to his country of departure until the end.