Selecao boss Fernando Santos announced his 26-man selection on Thursday afternoon, with Portugal looking forward to matches in Group H against Ghana, Uruguay and South Korea, starting from 24 November.
For Ronaldo, it's a fifth World Cup, an achievement matched by only four players previously.
Antonio Carbajal, Rafael Marquez (both Mexico) and Germany's Lothar Matthaus all played at a quintet of tournaments, while legendary Italy goalkeeper Gianluigi Buffon was an unused substitute in 1998, before featuring at the 2002, 2006, 2010 and 2014 finals.
Ronaldo, who became the all-time record men's international scorer last year, is targeting another record in Qatar as he looks to become the first player to score at five separate World Cups.