Did I overstay my F1 visa by staying in the US for 5 months after graduation?

To build on the otherwise great answer,

The actual question is: "Have you ever been unlawfully present (1), overstayed the amount of time granted by an immigration official (2) or otherwise violated the terms of a U.S. visa? (3)" I added the numbers. Does that help? The answers to the separate questions are: no -- you do not become unlawfully present on F-1 until an immigration official tells you to leave and similarly you didn't overstay the time because no such time was given. But the third is yes because the terms included you studying in the US which you were not doing. So answer yes and explain the truth in plain, simple words. "I entered on a F-1 Visa on date X, my I-20 had an end date Y, I graduated on date Z, I left on date U." Perhaps include a sentence or two but not much more about why you didn't leave when you should've. (Let's hope you were not working illegally.)

Your next question will be, what are your chances.

Depends.

If this was like five plus years ago, you have a spouse and a house and you are seeking a visa for a legit business reason like to enter for a few days to install or repair a highly complex piece of equipment? Your chances are great.

If this was like 2-3 years ago, you have practically zero ties to your country and want to be tourist for two months during COVID? Do not even bother filing because each refusal just will make the future applications harder.

Consider what the officer is going to be concerned about when you are asking for a B1/B2 visa: are you going to leave the country on time or are you going to become an illegal worker or illegal immigrant? Your credibility is lower than a person with no such history so you need to have an unusually good story on why are you entering and why can you be expected to leave. And Covid makes this a lot, lot worse: all the conferences and business meetings went virtual and it's complicated and risky being a tourist.

First of all, the visa is irrelevant. US visas are only for entry, and the visa expiration date has nothing to do with how long you can stay in the US.

As F1, you were almost certainly admitted for "D/S" on your I-94, which means your F1 status does not have a definite end date. You remain in F1 status indefinitely, as long as you comply with the rules of F1 status. This includes having a valid I-20 and remaining in good standing with your program of study. You also remain in F1 status for 60 days after successfully completing your program.

It appears from your description that you graduated much sooner than your I-20 end date, and your I-20 was not updated to reflect the new graduation date. After your graduation, even though your I-20 had not expired, you were no longer studying in the program that the I-20 was for. Therefore, you cannot remain in status on the basis of that I-20. You remained in status for 60 days after your graduation per F1 regulations. After those 60 days, you were out of status.

So, unless you had a pending OPT application or a pending Change of Status application, I think the answer should be Yes, you did "overstay". However, you did not accrue any "unlawful presence" because your I-94 had "D/S", and you thus could not have stayed past the date on your I-94.