Bishops of Rome and the Popes: 2 popes
Marcellus I   308-309  
Marcellus II   1555  
Fictional Characters from Plays and Musicals: 1 character
Marcellus Washburn   1957   The Music Man  
Notable Athletes: 1 boxing
(boxing) Muhammad Ali (middle name Marcellus)   1942-2016  
Saints: 5 saints
Saint Marcellus I   255-309  
Saint Marcellus the Centurion   ?-298  
Saint Marcellus   ?-304  
Saint Marcellus of Apamaea   ?-389  
Saint Marcellus   ?-510  
Shakespearian Characters: 1 character
Marcellus   Hamlet