49ers Owner Jed York Allegedly Arranged Trailer Park Tryst in Prostitution Arrest

San Francisco 49ers owner Jed York got collared by police over the weekend on suspicion of engaging in prostitution ... and the details of the bust are super embarrassing.

According to court docs ... Jed went hooker hunting online ... and responded to an ad on an escort website. He "arranged to have sexual activity with the female in exchange for $140" ... and the randy rendezvous was at a trailer park, The California Post reported.

The docs say Jed went to the trailer park, where he was greeted by the fuzz ... and not a floozy.

Jed was busted and booked into county jail on two charges ... engaging in prostitution and possessing criminal tools ... and he cut a plea deal with prosecutors and pled no contest to disorderly conduct and possessing criminal tools.

It sounds like the "criminal tool" was his cell phone.

The docs say cops found Jed had "in his possession his cellular device which was used to arrange the criminal act."

A judge sentenced York to one day in jail on each count, served concurrently, with credit for time already served ... and ordered him to pay $1,150 in fines.

Jed, who is from Ohio, is a married man. He and his wife, Danielle, have two sons.

The NFL tells TMZ Sports ... "We are aware of the matter which will be reviewed under the personal conduct policy."

The Niners also commented, but said a whole lot of nothin'.