Marion is technically unisex, but it's been traditionally used for boys for ages.
Marion Morrison is the most famous case; he's better known as
John Wayne.
Additionally, the
-on ending looks more masculine to me than the
-an ending.
So, I prefer
Marion for boys (as a masculine form of
Mary) and
Marian for girls.
True,
Marie and
Maria are used in French-speaking and Spanish-speaking countries, respectively, as male names--usually as mns, paired with 100% masculine fns--, but here in NA that practice is uncommon.
Marion is a more familiar, perhaps more accepted alternative if you want honour a
Mary by naming your son after her... or if you just like the name.
Both
Marian and
Marion are dated, yes, but that doesn't bother me at all. I think many dated names sound very refreshing amongst the sea of today's popular names.
Miranda