The joint bid defeated Morocco’s application with 134 of the 200 votes cast at the FIFA Congress in Moscow on Wednesday.
It marks the fifth time the North African country has failed to secure the right to host the international football tournament.
Morocco secured 65 votes, with the one remaining going to “none of the bids”.
The tournament will be open to 48 countries for the first time in 2026, with FIFA deciding to increase the number from 32 teams in January 2017.
The 2018 tournament kicks off in Russia on Thursday and the 2022 World Cup will be hosted by Qatar.
This was the first World Cup vote since 2010, when US and Switzerland investigators unveiled corruption on an unprecedented scale afterwards.
US soccer president Carlos Corderio said after his bid’s success on Wednesday: “It’s a bit emotional for us today.
“Thank you so, so very much for this incredible honour.
“Thank you for entrusting us with the privilege of hosting the FIFA World Cup in 2026.
“The beautiful game transcends borders and cultures.
“Football today is the only victor.
“And in that spirit we wish all Russian hosts and all the teams competing here the very best of luck.”
President Donald Trump welcomed the news, tweeting: “The U.S., together with Mexico and Canada, just got the World Cup. Congratulations – a great deal of hard work!”
Despite the latest setback, Morocco vowed to continue its bid to host the tournament in future.
Morocco FA president Fouzi Lekjaa said: “I would like to reaffirm the determination of my country, Morocco, to continue to work for football, to work for the youth and also to realise some day our dream to host the World Cup in Morocco.”
Russian president Vladimir Putin had earlier made a speech at the congress, during which he praised FIFA’s “commitment to the principle of sports without politics”.
England, like Morocco, knows the feeling of falling short in the bid to host the World Cup.
The Football Association has not hosted the tournament since 1966, having failed in bids for the 1990, 2006 and 2018 tournaments.
The FA was among the first to congratulate the US’ joint bid with Mexico and Canada.
An FA spokesperson said: “We congratulate the USA, Canada and Mexico on winning the bid to host the 2026 FIFA World Cup.
“Both bids were of a very high quality and we welcome the fact that the bidding process was both open and transparent.”
The announcement came as Spain sacked their head coach Julen Lopetegui a day before the World Cup gets under way in Russia.
The 51-year-old had been appointed Real Madrid manager in a move which reportedly left the Spanish FA president feeling “betrayed”.