| F.C. Porto
| 1939–40 Primeira Divisão|
The 1938–39 Primeira Divisão season was the fifth season of top-tier football in Portugal. With the Portuguese football reform of 1938, the experimental league became the most important competition of the Portuguese football calendar and began defining the Portuguese champion. To mark this the competition was renamed Campeonato Nacional da Primeira Divisão (National Championship of the First Division) or Primeira Divisão for short.
1938–39 Primeira Divisão Wikipedia
It was contested by 8 teams, and F.C. Porto won the championship.