The relationships were sexual during the course of the last six years at HMP Berwyn in Wrexham, Wales.
The remaining women were disclosed as a result of Freedom of Information requests made by The Mirror, while three of the women were sentenced to jail.
In order to send her lover Alex Coxon, 25, selfies via Snapchat, Jennifer Gavan, 27, smuggled a phone for him in November and was sentenced to eight months in prison in December.
She was also caught kissing him during the relationship that went on from April to July 2020.
The officer pleaded guilty to misconduct in public office after she accepted £150 to bring in the phone.
In 2019, Gunn was jailed for one year after having a fling with ‘dangerous’ inmate Khuram Razaq, 29.
The criminology and psychology graduate made numerous sexual phone calls to him while he was serving a 12-year sentence for conspiracy to rob, and smuggled in a pair of her knickers for the prisoner.
A search of her bedroom revealed snaps of the pair kissing and hugging while in his cell.
That same year, Emily Watson was jailed for one year for performing a sex act on prisoner John McGee.
Mold Crown Court heard she spent so much time with him staff became suspicious and launched an investigation.
They had been alone together in his cell on three occasions, when she performed a sex act on him twice and had intercourse once.
Staff have since been given corruption prevention training and the prison’s security has been enhanced.
A Prison Service spokesman said: ‘The overwhelming majority of Prison Service staff are hardworking and dedicated and we will not hesitate to punish those who break the rules.
‘Over 500 members of staff at HMP Berwyn have undertaken corruption prevention training in the last 18 months and our enhanced security is protecting the prison against attempts to smuggle illicit items inside.’