Is it ok to marinate chicken in lemon and orange juice overnight in fridge?

Yes! (feel free to add a tablespoon of soy sauce, or teriyaki sauce)

Sure, why not?

Isn’t that like a Ceviche with poultry? I have now idea if it works the same as fish.. More info.

You can marinade chicken overnight, however it may cause the chicken toughen. Make sure you add some olive oil to your marinade. Usually two hours is enough time for a citrus marinade for chicken.

More information about using marinades that might be helpful.

Yeah, to elaborate on what @PandoraBoxx & @johnpowell said, the citric acid in the juice can actually “cook” the chicken…it denatures the proteins & the meat will no longer have the flavor/texture of raw meat. An oil based marinade is fine overnight, but if you’re just talking the juice, I would limit it to a much shorter time.

Well, I dont think there are any laws against it.

Yes, as long as you don’t drink the marinade afterwards.

I would think that with chicken, you’re probably better off using herbs in milk for an overnight marinade. A marinade of mostly citric acid as in lemon and orange juice might partially cook the meat (as in a ceviche, as mentioned previously) if left overnight and could toughen the meat somewhat during cooking. Including a little lemon juice or orange juice in the mix should work out fine, but be careful not to overdo it on an overnight marinade.

I marinated chicken in sour grapefruit juice for several days once—I forgot that I had put it in the back porch fridge. I cooked it up and it was great. I’ve done it deliberately several times since then.

Yes, that is basically a mojo marinade http://allrecipes.com/recipe/mojo-grilling-marinade/detail.aspx or sour orange.