Adesanya, 30, is second on the list as he had an impressive year after winning all his three bouts in the year under review, and also emerge the undisputed UFC middleweight champion in the process.
His last bout earned him the prestigious title having defeated Robert Whittaker in a title unification bout on October 6, 2019.
Earlier in the year, Adesanya beat the duo of Anderson Silva and Kelvin Gastelum via unanimous decisions and won Fight of the Night award on both occasions.
Kamaru, on the other hand, is fourth on the list and he is battle-ready for his last fight of the year against Colby Covington on December 14, 2019.
It would be recalled that the 32-year-old defeated Tyron Woodley in March to emerge the new UFC Welterweight Champion through a unanimous decision.
The Auchi born fighter will be hoping to cap his year off on a winning note next month.
Meanwhile, American MMA fighter Henry 'The Messenger' Cejudo finished top of the chart after putting up impressive performances in all his fight in the year.
Jorge 'Gamebred' Masvidal, another American fighter came third, after Adesanya, while Francis 'The Predator' N'Gannou completes the top five positions on the ranking.
Below are the top ten fighters of 2019
Henry 'The Messenger' Cejudo
Israel 'The Last Stylebender' Adesanya
Jorge 'Gamebred' Masvidal
Kamaru 'The Nigerian Nightmare' Usman
Francis 'The Predator' N'Gannou
Donald 'Cowboy' Cerrone
Jon 'Bones' Jones
Ryan 'Darth' Bader
Dustin 'The Diamond' Poirier