Die KMB bringt sich auf internationaler Ebene im Dachverband "Unum Omnes", der internationalen Vereinigung Katholischer Männer aktiv ein.
Die Vereinigung wurde 1948 in Lourdes gegründet. Die Ziele und Prinzipien der Arbeit der Internationalen Ebene wurden folgendermaßen definiert:
- to help men to realize their potential in life as Catholics
- to encourage them to assume their rightful role in the Church and in the Society
- to promote the family as a source of human life and as the sphere of their responsibility and action
- to promote the establishment of catholic men organizations
- to foster dialogue between catholic men organizations
- to promote relations with national and international organizations
- to represent the hopes and the expectations of men in all fields of life