Garden City police arrested Robert S. Miller, 33, on Saturday afternoon at the Sun Liner Motel on Chinden Boulevard.
Sgt. John Goodman said police followed a tip from someone who said that a man had been soliciting a 15-year-old girl through a social media site.
Miller is a parolee and registered sex offender. He was booked into the Ada County Jail and charged with enticement over the internet, a felony.
He will be arraigned on Monday.
The intended victim, who had been communicating with Miller, never had contact with him.