The average salary for a Forensic Psychologist in the UK is: Â£47,125. Job profile for a Forensic Psychologist-we do not currently have a job profile for this role on site, if you are able to write one then please Send it to us-you will be fully credited on site.he average salary in 2011 was Â£40,000, based on 1 respondents (a difference of 48% from the 2010 figure. The median salary for a Forensic Psychologist based on all salary survey responses is: Â£35,000.