Cavendish and the now retired Bradley Wiggins teamed up for the event last year and finished second to Belgian duo Kenny de Ketele and Moreno de Pauw. Cavendish and Wiggins then went on to win the Gent Six Day.
"Taking on Six Day London with Brad last year was an unforgettable experience," Cavendish said in a statement. "It was our last event together in this country and going out in front of full crowds for six nights was immense.
"It's easily the best track cycling event in the UK and the best part of it is that it’s only two years old. The organisers want to make it the best it can be and I want to help them do that."
Cavendish added that he is unsure just who he will partner, Quick-Step Floors' Iljo Keisse is a former six-day partner, and will make the announcement in due course. "I'll sit down with Madison Sports Group and we’ll have a chat about it. I've got some ideas, I'm sure they will too and we'll sort it out soon. Whoever it is has got big shoes to step into." he said.
The third edition of the Six Day London will again take place at the Olympic Lee Valley VeloPark. Madison Sports Group Chairman Michael Gollner also confirmed that Amstel Beer will come onboard as a new sponsor from this year.
"You only have to glance at Mark's record to see he is one of the giants of the sport and so for him to commit to our event is big news for us," Gollner said. "This year will be our third event in London and we aim to improve it year on year, so I'm confident it will be the best yet."
The Six Day London is part of the Six Day Series that also includes events in Amsterdam, Berlin, Copenhagen and Mallorca.