It’s common for modern viewers to think of gold diggers as female, but this is only true in modern times. In historical eras where men controlled all their wives’ money, and received dowries upon marrying, they were much more likely to be gold diggers than women. The actual term “gold-digger” is rarely applied to men however; a male gold-digger is normally called a “fortune hunter”. If you go back far enough, you’ll find that all gold diggers were men, because marriage was originally an agreement made between the groom and the bride’s father, with the bride having little to no say in the matter. It’s therefore common in historical texts for the male to be the gold digger, but it isn’t always spelled out. An excellent example is in Emma, where Mr. Elton is never actually referred to as a gold-digger despite copious evidence that he is. Austen probably thought it too blindingly obvious to mention.
TV Tropes explains male gold diggers: