How do you become a US Ambassador?

Yes, a Presidential appointment and Congressional approval is the ticket for a job as an ambassador. It usually goes to those with experience in overseas affairs ... and those, especially in the smaller cases, some sort of political connections to the President. It's often used as a reward, particularly in the case of smaller countries. I would say you should broaden your list of possible career choices. If you know political science and a foreign language, you might be handy to a variety of outlets, including businesses doing work in both countries. An ambassador's job would merely be the luck of the draw.

You have to go to the best schools (Harvard, Yale, etc), join the foreign service and work your way up. In reality you have to know someone who is politically important and/or be super rich. The Japanese Ambassador is a really plumb job, a lot of people would want it. Major in Political science, economics, or international studies. Best of luck

Asking how to become an ambassador is like asking how to become a CEO of a Fortune 500... It will have to start with small steps. In your case, the foreign experience and degree should help you land a civil service/foreign services job. Spend a decade or so and ensure that you get the right experience. After that, continue in public service, perhaps study further at an Ivy and then the rest should follow

International affairs and relations and political science are what you need to major in. After that work your way up in the government for years till maybe you get a chance.

The USA is probably the only nation where somebody with absolutely no experience in politics or international studies can become an ambassador. In the USA you BUY yourself a posting as an ambassador and the bidding war is on right now... in the election! The people who contribute the most money to the new president's campaign get to choose if they want an overseas posting as ambassadors. It is basically the highest contributor gets the first choice which is usually Paris (apparently). After this presidential election almost all of the USA's ambassadors will be recalled from their overseas postings and replaced. This is only how it works in the US. Crazy huh?

You know someone and have a lot of money (no kidding). Foreign service does not automatically end up in ambassadorships, except for very small countries. The larger and more important countries are presidentially appointed and are based on who you know. International study is always important.

Tip: It's not what you know, it's who you know.

I have know idea.