Is Judoonian a language, and if so is there an official translation

Out of universe, no - Judoon is not a language that has been created with any particular care and there is no way to translate the Judoon heard in the television programme.

There are a couple of Judoon 'translators' on the internet, and as far as I can tell, they are just a novelty. They each seem to use some kind of internal logic for the 'translation' process, perhaps an algorithm that ensures you get the same result from the same input, but the output from each site does not match.

For example, I ran the sentence "This is a test to see if it matches" through two Judoon translation sites:

• This site returned: "Slotho solololololo ooh test toh see fio ioh matches"

• This site returned: "to ho kro so sho kro so sho blo sho to flo so to sho to plo sho so flo flo sho kro fo sho kro to sho mo blo to co ho flo so"

The latter site I used above does contain a rather detailed description of how English is 'translated' into Judoon:

The Judoon translate by splitting words into individual letters then adding an "o" to all the letters.
All Judoon word syllables start with a consonant.
Judoon replace the vowels with the consonant that is closest to the vowel in the alphabet and then add a "C", "L" or an "R" etc. to it to make it a double.

All of which sounds very plausible, but if that is the logic used in the show then it ought to be able to translate dialogue from the show back into English.

In 'Fugitive of The Judoon', the first complete line of dialogue spoken after the Judoon teleport onto the college green is:

So Zo Ro. To Sho Fro. So Zo To. No Fo Lo.

Running this through Whooligan's translator I get:

szr . t = . szt . nfl .

I've tried a few lines from the show, taken from transcripts online, and they all return rubbish, not English.

The limitation of the 'language' becomes obvious when you realise that there can only be 21 'words' in the language - the 21 consontants in the English alphabet followed by the vowel 'o'.

It is worth mentioning that a Judoon appearing in 'Fugitive of The Judoon' was named 'Pol Con Don', and this was a tribute to real-life Paul Condon, a fan and friend of Chris Chibnall. If the language used in the show followed strict rules then they wouldn't have been able to make this out-of-universe tribute.

It is also worth mentioning that, IN-universe, Judoon is one language that the TARDIS translation matrix seems to ignore. Other aliens appear to speak English because the TARDIS telepathically translates for the Doctor's companions (and us, the audience), but Judoon language is never translated - the Judoon themselves have to 'assimilate' the language and use their own translators. It is reasonable to assume that their language could actually be some kind of encrypted communication.