When I was 10 or something, the Malaysian version of Who Wants to be a Millionaire (WWTBAM) even has asked a question about it. This was c.2000 CE.
It's no single strait - in fact one WWTBAM question did mention that there's a "North Channel" (Selat Utara) and "South Channel" (Selat Selatan). Of course - relative to the main island.
edited Strait to Channel
Now this. https://www.openstreetmap.org/way/1134175227
I believe someone referred to Wikipedia: https://en.wikipedia.org/wiki/Penang_Strait
Can I say that the Wikipedia article is somewhat misleading?