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.
1. Most Wanted
Police have named and released photographs of 17 men officers want to speak to about offences including rape and murder Photo: SYP
2. Ahmed Farrah
Detectives investigating the murder of 21-year-old Kavan Brissett in Sheffield believe Ahmed Farrah could hold vital information.
Farrah, who is also known as Reggie, is believed to have been involved in the same incident in which Kavan was stabbed in 2018. He turned up at hospital with injuries on the same night.
If you see Farrah, call 999. Photo: SYP
3. Mohammed Anwaar
Detectives are asking for help to trace Mohammed Anwaar, who is wanted for failing to appear at court.
He is charged with two counts of conspiracy to supply Class A drugs, two counts of money laundering, possession of cannabis and possession of a firearm.
Call 999 straight away if he is spotted. Photo: SYP
4. John Eric Wells
Officers in South Yorkshire Police's Major Crime team are asking for help to find wanted man John Eric Wells.
Wells is also believed to go by the names Howard Walmsley and Howard Hemmings.
The 61-year-old, who is originally from South Yorkshire, is wanted in connection with three high value romance frauds, during which three victims lost money totalling more than £400,000.
The offences are reported to have taken place from September 2014 onwards. The victims lived in locations across the UK including Doncaster, Sussex and London.
Police would like to hear from anyone who has seen or spoken to Wells recently, or has information which may help officers with their enquiries. It is possible Wells is currently living outside the UK.
If you see him, or you have any information which may help, call South Yorkshire Police on 101 quoting investigation number A54532/17. Photo: SYP