Connor Smith -- a former MTV star from 2015's "Are You the One?" -- has been arrested in Florida for allegedly trying to hook up with an underage girl ... bringing a year-long manhunt to an end.

The 33-year-old was booked into custody Thursday afternoon, according to an inmate log from Pinellas County, Florida -- following reported sightings of him from the Sunshine State.

The ex-reality show contestant had been wanted in the state of Illinois since February 2023 ... where the Lake County Sheriff's Office said he interacted with an undercover detective online for weeks, thinking the cop was a 15-year-old girl.

He allegedly sent explicit photos and videos of himself -- and planned to meet up with the phantom kid to engage in sex acts Feb. 9 ... but when officers moved in to apprehend him, he fled in his pickup truck.

The following day, Lake County obtained a warrant for his arrest ... on felony charges of traveling to meet a minor, and grooming and disseminating harmful material. A judge also signed off on a million-dollar bond if he were to be captured and arrested.

In a previous run-in with the law, Smith was arrested on a similar charge in 2021 -- this after he allegedly raped a 16-year-old girl in Indiana.

The account the alleged victim gave police was brutal ... and he ended up getting picked up in neighboring Chicago. Charges were dropped against him in September 2022 when the victim stopped cooperating with law enforcement.