The former Tottenham Hotspur player has been forced to hang up his boots at the age of 26 after accepting that returning to the pitch would present too many risks to his health.
Mason, who signed for Hull from Spurs in 2016, fractured his skull during a collision of heads with Chelsea defender Gary Cahill in January 2017.
The midfielder's emotional statement can be read in full below.
"I can confirm that following specialist medical advice I am having to retire from playing professional football. I have worked tirelessly in order to be able to return to the pitch. Unfortunately, having taken expert medical advice I now have no option but to retire due to the risks involved given the nature of my injury.
"I am and always will be eternally grateful for the incredible network of people around me who have helped me to recover from what was a life-threatening injury in January 2017.
"Thank you to my amazing fiance, Rachel, who has been by my side and lived every single day with me since the injury, helping to give me the strength I've needed no matter how tough things got. We are so lucky to have now become the proud parents of our perfect baby boy George.
"To my Mum, Dad, sisters, and all of my family and close friends, thank you for everything. Despite how tough it's been and the challenges I've faced along the way you've all been there supporting me and words will never truly do justice to how grateful I am for your love and support.
"I would like to thank everyone at Hull City, especially the doc Mark Waller and all of the medical team for helping me to recover. Thank you to the chairman and the board for being so patient with my recovery and sticking by me.
"There are too many names to mention when it comes to talking about Tottenham Hotspur but I would like to say a special thank you to John McDermott, the gaffer and everybody at Spurs for helping me to achieve my dreams.
"I am so proud to have come through the ranks to play for my club, the club I love. To have had the honour of captaining the team fills me with immense pride. Thank you to all of my teammates over the years, there are too many to mention, it's been a privilege to play alongside you all.
"Finally, representing my country is an honour that nobody can ever take away from me and something that I am so proud to have achieved. I'm retiring from the game with my head held high having done everything in my power over these past 13 months to have given myself every opportunity to return to the pitch.
"I feel content knowing that I dedicated my life to be able to play football at the highest level, hard work really does pay off! I love the game, I always will and I am excited to see where football will take me next."