His deportation was delayed until he could be tried on a second charge of possession of pornography, CNN reported.
The court ruled Reynolds could spend five days in prison in lieu of paying a $100 fine.
Reynolds entered the country in November on a 14-day visa. His stay was extended, but officials said Reynolds stayed in Zimbabwe after the extension expired.
He was arrested Monday. Police said electronic devices found in his hotel room contained pornographic images.
Reynolds resigned his position as an Illinois congressman in 1995 after he was convicted of charges of criminal sexual assault, obstruction of justice and solicitation of child pornography.