Gwyneth Paltrow Kisser -- Officially Dumped by Wife ... Model Kirsty Hume Files for Divorce

Scottish supermodel Kirsty Hume is kissing her marriage goodbye months after her husband was famously photographed planting one on Gwyneth Paltrow.

Hume just filed for divorce from actor Donovan Jerome Leitch after more than 13 years of marriage -- and wants joint physical and legal custody of their 10-year-old daughter ... according to court docs obtained by TMZ.

Hume says they've been separated for the last 3 years -- backing up Leitch's story that they were already split when he kissed Gwyneth at a Dodgers game last September.

Paltrow -- who dated Leitch back in the '90s --- was still consciously coupled with Chris Martin at the time.

Hume is NOT asking for spousal support from Leitch ... so this one appears to at least be a civil uncoupling.