Bolt completed his amazing Olympic "triple triple" of 100metres, 200metres and 4x100m relay golds at the Rio Games in August despite missing much of the season through injury and took the award for the sixth time.
He clocked season’s bests of 9.81 and 19.78 to win the 100m and 200m in Rio and then anchored the Jamaican team to a world-leading 37.27 when winning the 4x100m.
He also went undefeated throughout the whole season at all distances, including heats.
Bolt, 30, plans to run the 100m at next year's world championships in London, seeking to add to his haul of 11 world titles.
Ayana produced a stunning run on the first day of athletics in Rio when she shattered the 10,000-metres world record that had stood for 23 years.
Her time of 29 minutes, 17.45 seconds smashed the mark of 29:31.78 that was set by Wang Junxia of China in 1993.
Ayana also took bronze in the Rio 5000m, her only loss of the year over the distance. She ended the year as the Diamond Race winner for that discipline.
She becomes the third Ethiopian woman to win the IAAF award, following Genzebe Dibaba in 2015 and Meseret Defar in 2007.
(Editing by Toby Davis)
