As a rule, names are not translated, so it's Brian. There is no German equivalent.
*I disagree to the above comment. There is Christopher, Cristóbal, Cristofer, Kristoff etc. The name Brian sounds Br(äi)an, my cousin was named Brayan as that's how Brian sounds more or less in our language (not German). As to the German equivalent of Brian, it remains unknown to me.
Brian. A Name is the same in every language.
Brian H. Wootton has written: 'German Shepherd Dogs' 'The German shepherd dog' -- subject(s): German shepherd dog, German shepherd dogs
Brian VanRiper's birth name is Brian VanRiper.
Brian Veronica's birth name is Brian Veronica.
Brian Bierwiler's birth name is Brian Bierwiler.
Betty Brian's birth name is Elizabeth Brian.
Doris Brian's birth name is Doris Brian.
Gwen Brian's birth name is Gwen Brian.
Brian Nohr's birth name is Brian Hestevold.
Brian Matzke's birth name is Brian Matzke.
Brian Wherret's birth name is Brian Wherrett.
Brian Heidik's birth name is Brian A. Heidik.