The list includes people believed to hold vital information about offences including murder and rape.
Some of those featured have been wanted by the police for years to help police crack a number of serious cases.
If you recognise anyone in the images, contact South Yorkshire Police on 101.
17. Jamie Frost
Police in Doncaster are appealing for information on the whereabouts of Jamie Frost. Frost, who is also known as James Frost or Adam Frost, is wanted in connection with reports of assault, criminal damage and taking a vehicle without the owner’s consent. The offences are alleged to have been committed this August in the Rossington area of Doncaster, an area Frost is known to frequent. Photo: SYP
18. Tyren Smith
Police in Sheffield are asking for help to find Tyren Smith. Smith, 18, is wanted in connection with several reported vehicle crimes committed in Sheffield and Barnsley between April and August this year. He is described as white, approximately 6ft tall, slim and has short, straight brown hair. He is known to frequent the Arbourthorne area of Sheffield. Photo: SYP