It cares me dick. (Spanish)

A few others from french :

J'en parlerai à mon cheval (I'll make sure to tell my horse)
Parle à mon cul, ma tête est malade (Talk to my ass, my head is sick/ill)
Je m'en tamponne le coquillard (no idea how to translate this, but here is a fun explainer, also in french)

Like water on a goose - Swedish

Just thought of one that takes a bit of explanation. In Swedish, much like German, words are joined to create longer words. Such as smörgåsbord(sandwich table). The smurfs in Swedish are therefore called gammelsmurfen (old smurf), "anything"smurfen. Because of this, people jokingly say "intressesmurfen antecknar" ( interest smurf is taking notes) to indicate that they don't care about what somebody is saying

It naps on my dick. (Bulgaria)

It sucks me (as in fellatio) an egg (testicle).

It sucks my dick.

I care a crow's nest (as in ships)

I care a turd.

I care a shit.

(Spanish again, we are creative people, as someone pointed out, the New World is way more colorful than Spain)

Not my circus, not my monkeys. (English)

Layeth thine eyes upon my field of fucks and behold that it is barren.

"I shit on it!" ("Szarok rá!") - in Hungarian.

Besides that just "I don't care." ("Nem érdekel.")

Maybe "Not even the dog cares, who lives in/at the shooting range." ("Lőtéri kutyát nem érdekli.") But it's more like for situations where you want to express, that nobody cares.

My dick hurts (Bosnian, Serbian, Croatian)

There are more vulgar ones in Spain:

Me la suda ("la" refers to "la polla"): It makes my dick sweat

Me la pela: It peels my dick

Me importa una mierda: That matters a shit to me

Obviously, this last one is closer to "I don't give a shit," but it's essentially the same sentiment.

Zero fucks given about this post. /s

One of the ways to say in Brazilian Portuguese: "estou cagando e andando"

Literally, "I am shitting and walking (simultaneously)"

n. I couldn't give a flying fuck (English English)
n+1. Ah couldnae gi a flyin' fuck (Scottish)

Greek Yeah I know of that phrase but it's not really used. It's as funny in Greek as it is in English.

Most common is "on my balls", the short version of I am writing it/him/her on my balls. Implying that you care so little you have the name of it/him/her written on your balls. Yeah it does t make much sense.

The lighter version (you would see in subtitles for example) is "to me there is no nail being burned". I don't know where it comes from. Must be something to do with nails being left behind when you burn wooden structure.

Edit: oh I remembered another; "I shat myself".

"My dick hurts" - various west Balkan languages.

It's me sausage actually. And it doesn't mean no fucks given, rather it is all the same to me.

Also in French: "it touches one (ball) without moving the other"

Flowers on my dick and bees all around is so mysterious

Swearing in Greece and across most of the whole region is hilarious. The actual "I don't care"/"zero fucks given" phrase is to write something on your balls or dick.

So many sayings are mother/whore/balls/dick based - not offensive phrases, just common sayings.

I’m Dutch. Never heard of that phrase. They probably mean “It can rust on my ass” “‘t kan me aan mijn reet roesten” still never heard people using that. Is probably regional.

Not as obviously cool as the above, but I always liked the way Tagalog (Philippines) works: wala akong pakialam. Literally translated, it's just "I don't care," but there's a layer of passive-aggressiveness that can make it really offensive.

To break it down: "wala" (Nothing, don't have) "ako(ng)" (I, me), "paki-" (polite request), "-alam" (to know).

Basically, that construction throws out the entire culture of politeness while blatantly saying you don't want anything to do with knowing about whatever that is. In many contexts, it's more offensive than swearing at the person.

More fitting would be German "das geht mir am Arsch vorbei" "it passes me by the ass".