Can you use American dollars in Malaysia?

Answer 1

As a general rule, no - Malaysians have their own currency (Ringgit) . There may be some exceptions. Thankfully, there are a lot of places to exchange currency in Malaysia, especially in the larger cities.

Answer 2

No, Ringgit Malaysia (RM) is the only currency commonly circulated in Malaysia.

However, in the border of south Malaysia (Johore Bahru, next to Singapore),

Singapore dollar is accepted.