The tournament will mark the centennial of the World Cup, which was first played in Uruguay in 1930.
After the inaugural matches in South America, the competition would relocate to Spain, Portugal and Morocco, where the remaining games would be played.
It marks the first time the World Cup will be staged across three continents and six countries.
"The FIFA Council unanimously agreed that the sole candidacy will be the combined bid of Morocco, Portugal, and Spain, which will host the event in 2030 and qualify automatically from the existing slot allocation," FIFA said in a statement.
"Additionally, having taken into account the historical context of the first-ever FIFA World Cup, the FIFA Council further unanimously agreed to host a unique centenary celebration ceremony in the country's capital, Montevideo... as well as three World Cup matches in Uruguay, Argentina and Paraguay respectively."
The 2022 World Cup was held in Qatar. Argentina are the defending champions.