Aidan McGuinness, 44, was reported missing from Hollesley Bay in Suffolk on Saturday morning.
Joshua Lewis Terry, 29, and Levi Mitchell, 39, are then understood to have absconded together later that night.
Suffolk Police have launched a hunt for the three and have warned the public to stay away.
The force received a call that Terry and Mitchell were missing from the Category D jail at around 7pm.
Terry is serving a two-year and four-month sentence for affray, threatening a person with a blade or sharp-pointed article in a public place and theft.
He has been described as 6ft 2ins with ginger hair and blue eyes.
The lag has stubble facial hair and a tattoo on his lower arm of a star.
Mitchell is 5ft 10ins with ginger hair and blue eyes. He is of a slight build with a goatee beard.
The inmate, who is serving a sentence for multiple burglary offences, also has a birthmark on his left arm and hand.
McGuinness is 5ft 10ins with brown hair and blue eyes. He is of a thin build with a clean-shaven face and a slight northern accent.
Police said he has a tattoo on his left wrist that reads “Zara“.
He is serving a three-year sentence for theft, fraud and possession of Class B drugs.
Police have asked anyone with information to call them on 101 quoting CAD 310 or CAD 311 of 21 October.