Yhyjyk

In every country, some names are particularly common: 'John' in the UK, 'Juan' in Spain, 'Ivan' in Russia. Those names are common almost to the point of being stereotypical (consider 'John Doe').

If I have no more than one or two characters from a particular place, is it bad form to use those extremely common names? On the one hand, those names are common, that's real life. It is quite realistic to have a character from that location carry that name. On the other hand, it feels almost lazy to have a guy from Spain named Juan, and his sister is of course Maria. Like I couldn't be bothered to do the research and find some other names, and went with the most stereotypical ones instead.

Is there a way to strike a balance between conveying a strong sense of location with the names, and not being "too stereotypical"? (My particular situation is a setting in space with people from all over.)

The problem about this is that most of the time we want to read something about special people. Sure, we want to be able to sympathize with the character and for example superhero comics have a history of making it look like everyone could be Superman - or Shazam the 14-year-old-boy-transformed-into-a-superhero - but characters in books, comics, etc. tend to be special in some regards. By giving your protagonist a name that seemingly every second person has they can appear quite boring.

What name do you think would be more memorable: "Shazam" or "Billy"?

Yes, the protagonist in the linked comic series is named "Billy", quite the typical name. But most people will likely find his superhero form more memorable. Maybe you could use this and give your "Juan" and "Maria" interesting and memorable nicknames. Especially if they have a name that seemingly everyone else around them had that could be a reason to try and stand out. How do your characters feel about their name? Do they like this typical name? Maybe they like the feeling of proudly representing the majority. Or maybe they want to be special. Different. Not just another "Juan" or "Maria".

A lot of this depends on the setting. In fantasy or sci-fi settings it's far easier to just come up with new names. In modern day settings like in a thriller you will more likely use "normal" names. But this also depends on a lot of factors. Are you in a rural area where older names are more present? Or a metropolitan city with influences from all around the globe? Is the social class of your characters focused on traditions or innovation?

As you mention that you have a setting with lots of people from all over the world you could use steretypical names a few times. Maybe one or two out of a group of five people would feel like something that can actually happen while still not feeling as if you were simply too lazy to look up other names. But you should think about other options to refer to these characters and you should think about how the characters feel about their own names.

There is nothing wrong with using common names for characters unless you over use them. If everyone has the most common names for their region, the readers may start paying attention to that instead of your story.

That being said, there are ways of playing with it. You could use it to break expectations. Maybe Ivan is from the UK?

Heck, any of them could be from the US.

Maybe have two characters named John. One will end up being called by a nickname. My name isn't incredibly common but for one event we had five people with my first name on a radio net. That was a fun mess. With 95 people on the radio net, last names were out as well.

Maybe have John meet Juan. Having the "same" name might be a running gag for the two.

I look for popular names, but not the MOST popular names. For example, I just googled "most popular names in the UK" and found this at the top link. An excerpt:

Boys

Oliver - 6,259
Harry - 5,031
George - 4,929
Noah - 4,273
Jack - 4,190
Jacob - 3,968
Leo - 3,781
Oscar - 3,739
Charlie - 3,724
Muhammad - 3,691

Girls

Olivia - 5,204
Amelia - 4,358
Isla - 3,373
Ava - 3,289
Emily - 3,121
Isabella - 2,627
Mia - 2,590
Poppy - 2,527
Ella - 2,452
Lily - 2,405

Just pick something not in the top 5, it would be realistic, but not obviously stereotypical of the region.

It is bad when your "national" character is one-dimensional. It is perfectly fine when this character is non-stereotypical.

Creating a "representative" characters with stereotypical names is a bad (and well-worn) practice when those characters also reinforce popular stereotypes of a certain nation or racial group. On the other hand, if such character has depth and well-developed, steretotypical name becomes insignificant.

This trope was humorously subverted in the 2002 movie The Cuckoo, in which one of the main characters, a Russian, has name "Ivan", but his newfound friend, Finnish sniper Veikko is not believing it because

when they first met and Veikko asks for Ivan's name, Ivan replies "Get lost!" (in Russian) - and this is how Veikko had called him ever since.