The simple answer is chorus, as a modulation effect, generally goes after distortion or any gain pedal for that matter. In fact they go pretty late in the chain and sit right before delay and reverb which typically go at the end.

Some say that it’s best to put a chorus pedal before distortion, while others say after. So, which is it? The answer, like with most things in music, is that it depends. It really depends on the sound you’re going for and the rest of your pedalboard setup. There are, however, some general recommendations.
Effect Categories
Let’s look at the different categories in order they’d normally be chained and what is contained in them.
1. Dynamics / Volume
This includes volume pedal, compressor, pitch shifter, tremolo, octave
2. Drive / Gain
Overdrive, distortion, fuzz, boost
3. Modulation
Chorus, phaser, flanger
4. Time-based
Delay and reverb
Read our other article for more information about chorus pedal placement in relation to other effects.
A Difference of Opinion
The reason we generally put chorus after distortion effects is because chorus will created multiple voices and when these are processed through a distortion pedal the sound can become muddy. It’s much better to make multiple voices out of the raw original distorted sound.
However, some actually prefer to put modulation effect before any type of distortion as it makes them less pronounced. It certainly sounds less 80s this way and many do want to avoid that more dated guitar sound.
Putting chorus first in certain contexts can make sense and you’ll only know if it works if you try it.
Another alternative if your amplifier has an effects loop is to run the chorus through it while leaving your drive pedals in front of the amp.
Conclusion
When wondering if you should put a chorus pedal before or after distortion, try both set-ups and see which you prefer. Ultimately, it is up to you and your own personal preferences as to which set-up sounds best for you and your playing style.
Remember this is your sound. Experiment and go with what you like the best.