Autumn Daly -- a contestant on "Big Brother 2" way back in 2001 -- has been arrested on a theft charge in Texas ... TMZ has learned.

Police arrested Daly last month in Lewisville, TX on an outstanding warrant for theft. Cops say they found AD after they tracked her car to a local retail store she owns called Encore! Encore!

An officer asked her if she had any warrants, and they say she confirmed she did. Police claim Autumn said she's in the process of taking care of the warrants but hadn't yet -- so, they arrested her.

Autumn was charged with property theft between $30k and $150k for an alleged 2023 incident. She posted the $2,500 bond.

As for the alleged theft itself ... we reached out to cops for more information, but they declined to share anything additional, noting it's an active investigation.

We reached out to Autumn for comment and she tells TMZ ... "It’s a retaliation attempt on the part of a former business associate who sued me in civil court and lost. It won’t stick and I’m in the process of suing them for $500K as well, so best I don’t say anything further."

Daly rose to prominence during the second season of 'Big Brother' ... becoming the third person booted from the house after nearly three weeks on the reality competition show. Dr. Will Kirby ended up winning the season.