He beat off competition from 47 other poets, most with experience far outstripping his own, over the five month show.
However, it is Hilal who has attracted much attention and divided opinion with her outspoken verse.
The fully veiled mother of four has been called "brave" for her poetry criticising Saudi Arabia's strict laws, like the segregation of the sexes and fatwas restricting women from working. But she has also received death threats on Islamist websites like Ana al-Muslim.
She won $816,816 in cash for coming third in the competition.
Million's Poet, funded by the Abu Dhabi Authority for Culture and Heritage, features the Arabian Peninsula's native Nabati poetry.
The winner of the show was chosen through a combination of the judge's evaluations and audience votes via SMS and in-theatre voting pods.
Al Ajami received 67 percent of the total number of public votes and judge points.
Second place went to Kuwaiti Falah al Mowraqi, who received $1.08 million prize money.