How do I invest in American stock market while living in Nigeria?

 Find an online broker that can accept you, do the forms (application forms, verify your identity and so on) and invest.

Nigeria isn’t a “black listed” country like some places, where hardly any brokers will accept - Somalia for example. There are plenty of options.

However, it depends how much money you have to invest.

Let’s keep this simple.

If the amount of money you have is pretty small and/or you can’t get the money out of Nigeria easily, then I would stick to local providers.

In comparison, if you have at least $500 a month to invest, or a decent lump sum, I would consider international providers.

Most people with money in the country want to diversify internationally and there is a reason for this.

It is safer and better.