Pueblo, CO from tv commercials or maybe Walla Walla, WA from Bugs Bunny.

Dildo, Newfoundland, Canada: 803 people as of 2021.

Someone here mentioned Vulcan, Alberta - however given the qualifiers of country and size, its 1769 people disqualifies it.

Also, though I am a Trekkie myself and know that Vulcan is well known in those circles, it's virtually unheard of outside them.

Meanwhile, Dildo:

https://www.cbc.ca/news/canada/newfoundland-labrador/odd-stories-of-2019-1.5389442

Wales has St. Davids - population c.1,750

Forks, Washington population of ~7000 made very notable due to the twilight series. Or Astoria, Oregon population of ~10,000 made famous by the Goonies.

The New Orleans French Quarter is easy to spot.

Byron bay. Bundaberg. Coon.

Fucking, Austria. Population of around 100 People. They renamed it to Fugging a few years ago

Well, Brazil is such a huge country and there are lots of smallest cities with still huge population.

Unfornately i would have to say that the smallest one and most famous would probably be because of some recent disaster and one I can remember is Brumadinho. Less than 40k people, a city destroyed after a dam collapsed and a lot of mud flooded everywhere, 5 years ago

Vulcan, Alberta.

Famous because of a spaceship that landed there once, I think.

Some people with pointed ears may have also been involved, but I would replicate that with a grain of salt. I haven't really looked into it.

Winnipeg, Canada (pop. 850k) has a famous namesake in Winnie the Pooh (who was named after Winnipeg) and has been in the Simpsons.

The Simpsons - That's it, back to Winnipeg!

Selma

Here in Illinois is Woodstock, at ~25,600 (2020 per Wikipedia). It was the town where Groundhog Day was filmed. There's even some small road signs here and there mentioning it for the rare tourist who comes to see it. Smallest place in the state I can think of, though there's smaller towns that have been used for movies.

Some upcoming off-brand Hallmark x-mas movie will feature local tourist trap town Long Grove IL, pop ~ 8,300 (2020 per Wikipedia). The director grew up near there so knew about it and thought it'd be perfect for his movie.

Aramoana here in New Zealand. It has a population in the low hundreds and it is famous for a horrible massacre in 1990. The cops here don't usually have guns and in a little place like that there are often only a handful of police that are anywhere in the general region.

https://en.wikipedia.org/wiki/Aramoana_massacre

Bobcaygeon, population 3,500.