In Spain we use “Fulano de Tal”. It seems Fulano comes from the arabic language, meaning “Anybody”. We use it when we don’t the name of a person we are talking about, or we really don’t care to know the name. Apart of Fulano, we also use Mengano.
Fulano/Mengano for men, Fulana/Mengana for women.
I guess our John/Jane Smith would be Pepe/Pepa García.
Shut it!