Stewart Regan, chief executive of the SFA, said expansion would allow the domestic game to develop with the extra finances that qualifying for the quadrennial football showpiece would bring.
Scotland are struggling already to qualify for the 2018 finals in Russia and have not appeared at the World Cup finals since France hosted them in 1998.
"We are pleased with the news that the FIFA World Cup will expand to 48 teams from 2026," said Regan in a statement published oin the SFA website. "We believe this is a positive step, particularly for the smaller nations, and will allow more fans across the globe to revel in their country's participation at a FIFA World Cup Finals. "This will also allow these nations to invest further in their footballing infrastructure and youth development, which in turn can yield significant social benefits."
Regan added that the achievements of the smaller nations at an expanded Euro 2016 -- Iceland eliminated England and Wales got to the semi-finals -- had shown how minnows internationally could enhance a major finals.
"The exploits of Wales, Iceland, and Northern Ireland at EURO 2016 showed what an impact the smaller teams can have, and how beneficial to a tournament their participation can be," said Regan. "A greater eclectic mix of footballing cultures at the FIFA World Cup will create a bigger and better atmosphere than ever before."
Follow the live coverage match of the 2018 World CuP qualifying between: Scotland-England