Kelley Wolf is in trouble again with the law in Utah … this time she landed in jail for two misdemeanors after posting a series of disturbing Instagram messages, TMZ has learned.

Kelley  — the estranged wife of “Party of Five” star Scott Wolf — was taken into custody Tuesday night and booked into the Summit County Jail for electronic communication harassment and electronic disclosure of personal identifying information.

She hasn’t gone before a judge so no bail has been set. Police have not released a detailed narrative, but we’ve reached out to them … no word back yet.

Back in June … Kelley made a desperate 911 call, asking police to help retrieve her belongings from the Park City home she shares with Scott, her soon-to-be ex-husband.

During the call, Kelley revealed she got into a heated argument with her 16-year-old son over a cell phone, before locking horns with her brother-in-law. She also said Scott was being “controlling” and “insane” during their ongoing divorce.

BTW, Kelley and Scott share three children together — Jackson (16), Miller (12), and Lucy (11).

Hours earlier, Kelley was staying at the Sundance Mountain Resort in Sundance, UT, where she was detained by sheriff deputies after someone overheard her make concerning remarks to family members and called police.