According to new legal docs, obtained by TMZ, the Netflix star -- who's been on the show for a few seasons now -- Lazkani filed for divorce against her husband Jeff Lazkani ... and she's citing irreconcilable differences as the official reason.

Per the paperwork, Chelsea doesn't seem to know the exact date of separation -- marking it as TBD -- but one thing she does know for sure is that she's ready to throw in the towel.

Chelsea and Jeff share two young children together -- 3-year-old Melia and 5-year-old Maddox -- and in her divorce docs, Chelsea is signaling that she wants joint physical and legal custody between her and her estranged husband.

On the issue of money ... Chelsea is asking for spousal support, but interestingly -- she's not asking the court to terminate Jeff's ability to ask for alimony himself. There's no explicit mention of a prenup in the docs ... but it's unclear if they have another type of agreement.

Chelsea is saying that their division of assets needs to be determined in court.

The ex-couple has been married since 2017, and they actually met on Tinder. Jeff has been featured on the show during Chelsea's run on 'Sunset' -- and while he isn't prominently featured as a main character, he does pop up here and there in CL's on-camera life.