The offenders are wanted for crimes including murder, large-scale, drugs trafficking and supplying firearms and ammunition.
James Stevenson, otherwise known as Jamie, is wanted over the seizure of approximately one tonne of cocaine found in an unaccompanied freight arriving at the Port of Dover in September 2020, and the production and supply of approximately 28 million Etizolam "street valium" tablets that were seized following a raid on a suspected pill factory in Kent in June 2020.
The 56-year-old, whose last known address was in Fishescoates Gardens in Rutherglen, Glasgow, is also wanted in connection with two suspected arson attacks on properties in the Lanarkshire and Forth Valley areas in May 2020.
Stevenson is stocky and has a scar on his face and he is known to have connections in Barcelona and Alicante.
Members of the public have been urged not to approach Stevenson if they see him, but instead contact the relevant authorities.
The National Crime Agency's (NCA) regional head of investigation for Scotland, Gerry McLean, said: "Stevenson is one of Scotland's most wanted fugitives.
"He knows we are looking for him in connection with organised crime on both sides of the border.
"The NCA and Police Scotland will not rest until he is captured. Anyone who is helping him stay on the run will be targeted too."
The NCA's Most Wanted campaign is run in conjunction with independent charity CrimeStoppers, Spanish law enforcement and UK policing.
All the men featured are believed to have links to mainland Spain and the Canary Islands.
Steve Rodhouse, the NCA's director general of operations, said Spain is "not a safe haven" for the fugitives.
"Many of these fugitives will be trying to blend in to the large British communities who have made their homes in Spain, and if you are resident, you may know one of them from your town or village," he said.
"Loyalties change over time and we urge anyone with information about these men to help us find them."
Among the most wanted is Nana Oppong, 41 who is on the run from Essex Police for the drive-by murder of grandfather Robert Powell, 50, who was shot eight times with a 9mm pistol on 13 June 2020.
Jack Mayle, 30, is wanted on suspicion of supplying Class A drugs and supplying a drug line in south London, and he is known to carry weapons.
Callum Halpin, 27, is on the run from Greater Manchester Police for the murder of drug dealer Luke Graham, 31, and the attempted murder of Anton Verigotta in a drugs turf war in June 2018.
Two men from Cardiff, Asim Naveed, 29 and Calvin Parris, 32, are wanted by South Wales Police for Class A drugs offences allegedly organised by using the encrypted comms platform EncroChat.
The others include:
- Benjamin Macann wanted by Norfolk Police for alleged drug supply
- Jack Mayle wanted by Surrey Police for alleged drug supply
- John James Jones wanted by Lancashire Police for an alleged stabbing attack on two people
- Callum Michael Allan wanted by Northumbria Police for allegedly supplying drugs, assaulting an emergency worker, affray and dangerous driving
- Dean Garforth wanted by Cheshire Police for alleged drug and ammunition supply
- Joshua Dillon Hendry is wanted by Humberside Police accused of drug trafficking and supply
- Mark Francis Roberts is wanted by Merseyside Police for alleged grievous bodily harm
Anyone with information about one of the Most Wanted is urged to call CrimeStoppers anonymously on 0800 555 111, and callers in Spain should call the freephone Spanish number 900 926 111, which will be answered by CrimeStoppers in the UK (using translation if required).
Alternatively, members of the public can fill out an anonymous online form at the UK charity's website crimestoppers-uk.org/fugitives.