Do they speak canto in Hong Kong?

Excuse me, but could you clarify something for me? In Hong Kong, is it common for people to speak Cantonese, or is it more of a mix of different languages? I've heard that Cantonese is widely spoken there, but I'm curious if it's the dominant language or if there's a significant presence of other tongues as well. Could you please elaborate on the linguistic landscape in Hong Kong?