2015 Six Days of London was a professional track cycling event held at the Lee Valley VeloPark in October 2015.

The primary event in the six day competition is the madison, occurring twice per night, in which teams attempted to lap the field.

The overall number of laps determined the winner of the completion, with ties being decided based on points earned in minor races, including the derny, team elimination and time trials.

[1] The first day didn't count towards the main competition, due to a clash with the European Track Championships in Grenchen which meant not all riders could be present.

Instead, a stand-alone single day solo competition was held under the title of the "1878 Cup", which was won by Mark Stewart.