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.
Roman Catholic Diocese of Saint Joseph was created in 1868.
Saint Malachy's Roman Catholic Church was created in 1920.
Roman Catholic Diocese of Saint-Claude was created in 1742.
Roman Catholic Diocese of Saint-Flour was created in 1317.
Roman Catholic Diocese of Saint Cloud was created on 1889-09-22.
Saint Stanislaus Roman Catholic Church Complex was created in 1897.
Roman Catholic Diocese of Saint Joseph at Irkutsk was created in 1999.
Roman Catholic Diocese of Saint Joseph at Irkutsk's population is 15,500,000.
Saint Mary of Sorrows Roman Catholic Church was created in 1891.
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-Jérôme was created on 1951-06-23.