Catacombs in Rome

Andrea, it has been a few years since we've done one but I'm not seeing anything on their individual websites that indicates a mandate for advance reservations except for larger groups. That said, check the websites yourselves, and Easter could be a busy time in Rome so to reduce waiting for the next tour in English, you might consider it. Here are the websites for the top 4:

Domitilla:
https://www.catacombedomitilla.it/en

Callixtus:
https://www.catacombesancallisto.it/en/index.php

Priscilla:
https://catacombepriscilla.com/en/home-eng-2/

San Sebastiano (we did this one):
https://www.catacombe.org

A little info about the catacombs? Ignore if you already know but so many visitors don't seem to understand what they'll be seeing that it's worth mention. I'll highly recommend some additional reading up before you go! :O)

They're only accessible with a tour, photography is not allowed, and respectful behavior is expected.

These are not similar to the catacombs in Paris, with arrangements of bones created after being moved from original locations. These were original burial chambers, and remains which occupied niches which had been opened, due to vandalism or other reasons, have been respectfully removed from routes the tours follow. They are considered to be sacred places.

They are interesting for visitors of any faith (we don't identify with any one of them) even though our particular tour was a bit heavy on Christian beliefs. It's the background about how the many miles of subterranean cemeteries came to be, - there are at least 60 of them in Rome; the vast majority inaccessible to tourists - the remains of very, very old decoration (the majority of which is early Christian), and burial customs of the time that are good reasons to go.

Not all burials, depending on the catacomb, were Christian. Some of the interred, such at San Sebastiano, were Jewish and non-Christian Romans too.

They are sometimes confused with the Capuchin Crypt, which is neither particularly old, compared to the 4 catacombs listed above, nor a catacomb. It's a "bone church": if it's bones you want, that's where you go. I haven't visited (nor intend to) but the website is here, and most of the same rules apply (no photos; respectful behavior; etc.)

https://museoecriptacappuccini.it/en/

Hope this helps!

I'd recommend the Catacombs of Priscilla, which is usually where I visit because I used to live near them and they are easier (in my opinion) to reach than the ones near/on the Appian Way. For Priscilla, I recommend reservations to be sure that you can have a tour in English.