The 27-year-old striker has signed a two-year deal, according to the Saudi Arabian outfit.
The Mali international has reportedly signed a two-year contract, as revealed by Al Nassr's Twitter account, though there are conflicting and unconfirmed rumours regarding the fee involved, if there is any at all, with the Al Nassr tweet referring to the player as a "former West Ham forward".
The striker's career in East London has been epitomised by an inability to fulfil much goalscoring potential whatsoever, though ironically, Maiga did score a superb goal in the recent home defeat to Bournemouth.
Having moved from Sochaux in 2012 for what the Mail reported to be £4.7 million, the 27-year-old would only score seven times in 43 matches for the Hammers, with his season's best total a mere four goals.
Undoubtedly a highlight of his time in England, which also saw him take in a disappointing loan at QPR, was a late League Cup quarter final winner in Tim Sherwood's first match in charge at Tottenham, with the Hammers knocking their rivals out on the way to recording three victories over Spurs in the 2012-13 season.
The forward's departure from the Boleyn Ground will leave the Hammers with even more depleted attacking options, having struggled with injuries this season.
West Ham fans took to Twitter to discuss the impending move, with many curious about the fee, and also waiting on confirmation by the selling club:
@ExWHUemployee am I the only one that wants maiga to stay. Frustarting to watch at times but potential is there. Good goal sat— Matt Finch (@MattFinch15) August 25, 2015
Is it April 1st? Modibo Maiga leaves Hammers for £6m!!! If so, how did they pull that one off?! #WHUFC— Anthony Khan (@AntKhan01) August 25, 2015
So Sakho's been arrested, and Maiga's due to be released on a free today, leaving us with 0 fit, senior strikers in the entire squad… #WHUFC— This Guy (@OfficialKempo) August 25, 2015
I'm still grieving the loss of Maiga...— West Ham Info (@WestHamsAll) August 25, 2015
Maiga is sold right after scoring that amazing goal?— Frederick (@FrederickRants) August 25, 2015