Commissioner Elizabeth Denham first revealed the award, designed to recognise excellence in the field of information rights, in January of this year.
At the time, she said it was specifically for practitioners who have made a real difference to how their organisations approach data protection.
Denham added: “As we approach GDPR and new UK law taking effect, it has been clear there are many success stories out there when it comes to individuals embedding a positive data protection culture in their organisation."
In a statement, the panel of judges said that the achievements of all the nominees "were extremely impressive and reflected their commitment to maintaining the highest standards and dedication to maintaining their own education and training, a massive factor in the success of a data protection officer".
And although exact details of how Watt came out on top have not been revealed, award panel member Paul Jordan, managing director Europe for the International Association of Privacy Professionals, said that she "clearly embraced her role as she was swiftly acknowledged as the chief architect for organisational change, which is possibly harder to achieve in the public sector as constraints can be harder to circumvent".
"Her initiatives have clearly been central to ensuring the organisation’s smooth and positive transition towards GDPR compliance,” Jordan added.
Watt said: "Data protection officers are increasingly important on the front line of the new digital society, ensuring the rights of the public are protected while also making sure their organisations are legally compliant.”