When I see Father Mulcahy (M*A*S*H) every now and again I see him wearing a grey sweatshirt with Loyola (with obvious Jesuit connotations) written across it. I was wondering, is there any indication that he was a Jesuit?
I believe you are correct. So does the MASH wiki:
In many episodes, Mulcahy is seen wearing a "Loyola" hoodie. This makes sense in that Mulcahy was a Jesuit and Loyola is a Jesuit school. In the final episode of the series, however, Mulcahy is seen wearing a "Wesleyan" sweatshirt; Wesleyan University, the alma mater of actor William Christopher, was affiliated with the Methodist Church until 1937.
He also apparently identifies himself as a Jesuit in the series but I cannot find specific season-episode citations.