Kipchoge, 31, beat his fellow Kenyan, 33, in a sprint finish in 2015.
Kenyan world-record holder Dennis Kimetto, third last year, is also confirmed for the event on 24 April.
It had already been announced that 2015's women's race winner, 28-year-old Ethiopian Tigist Tufa, will take on Kenya's two-time victor Mary Keitany.
Ethiopia's triple Olympic gold medallist Kenenisa Bekele and Eritrea's world champion Ghirmay Ghebreslassie, 20, are also due to take part in the men's race.
There will be 13 elite British male runners hoping to secure their place at this summer's Olympics.
Scott Overall and Callum Hawkins have already achieved the qualifying time and will guarantee their place in Rio de Janeiro if they are the first two Britons to cross the line.
Sonia Samuels and Alyson Dixon have run inside the women's qualifying time and will also guarantee Rio places if they are the first two British females to finish.
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Reigning champion Eliud Kipchoge will vie with two-time winner Wilson Kipsang for this year's London Marathon men's title.