The X Factor judge and Take That musician told The Mirror that he thinks he is too young to receive the honour and merely wants to be involved in "worthwhile" projects.
> Gary Barlow: 'Prince Charles inspired Diamond Jubilee single'
Barlow said: "I feel a bit young [for a knighthood], if I am honest. I don't wake up every morning thinking about that, I just want to do good stuff. When they asked me to be involved in the Jubilee concert, I knew what I could do to change it, to make it feel like a new concert.
"When they asked me to do the record ['Sing'], I knew I could have an effect on how it would feel. As long as I feel I could bring something to a worthwhile project, then I am always willing to be involved."
> Gary Barlow: 'The Queen wanted to know when Jubilee concert will end'
Barlow's Diamond Jubilee composition - on which he collaborated with Lord Andrew Lloyd Webber, Gareth Malone and the Military Wives Choir - saw him touring the Commonwealth to record samples for the song.
He recently said that the reception Prince Harry received in Jamaica was like "the first incarnation of Take That", and compared the prince to Robbie Williams.
Watch the video to 'Sing' below:
Photo gallery - 'Gary Barlow: On Her Majesty's Service' preview images: