US, Canada and Mexico will host the 2026 World Cup.
More than 200 national football federations voted at around midday local time in Moscow (0900 GMT or 1pm UAE time) at their annual meeting one day before the 2018 World Cup kicks off.
FIFA members had to pick between the financial security of the United States-Canada-Mexico bid where all venues are ready, and a Moroccan bid that needed to build or renovate all 14 stadiums for a 48-team tournament.
Mexico has twice hosted the World Cup, in 1970 and 1986, the U.S. hosted in 1994, while Morocco has lost in four previous bid campaigns.
Morocco's bid exists largely on paper - many stadiums would have been needed to be built and critics questioned how it would cope with a tournament that will be expanded to 48 teams in 2026.
FIFA inspectors had classified the north African nation's stadiums, accommodation and transport as "high risk", awarding it just 2.7 out of five, with red flags raised over several critical aspects of the bid.
A FIFA taskforce warned last month "the amount of new infrastructure required for the Morocco 2026 bid to become reality cannot be overstated".
The report left the US-Canada-Mexico bid as the clear front-runner after giving it a rating of four out of five.
With inputs from agencies