Generally, yes. However, there are other Catholic Churches that are not Roman but are in union with Rome, for example Maronite Catholics, who can be saints. In the early Church there were several Jewish saints who never were Catholic or Christian - St. Anne, St. Joachim, St. John the Baptist for example.
Saint Malachy's Roman Catholic Church was created in 1920.
Roman Catholic Diocese of Saint-Flour was created in 1317.
Roman Catholic Diocese of Saint Joseph was created in 1868.
Roman Catholic Diocese of Saint-Claude was created in 1742.
Saint Mary of Sorrows Roman Catholic Church was created in 1891.
Roman Catholic Diocese of Saint-Jérôme was created on 1951-06-23.
Roman Catholic Diocese of Saint Thomas was created on 1960-04-30.
Saint Stanislaus Roman Catholic Church Complex was created in 1897.
Roman Catholic Diocese of Saint-Hyacinthe was created on 1852-06-08.
The population of Roman Catholic Diocese of Saint Clement at Saratov is 47,000,000.
Roman Catholic Diocese of Saint Clement at Saratov was created in 1999.
Roman Catholic Diocese of Saint Catharines was created on 1958-11-22.