The commemorative coin with a face value of 5 pounds ($8) went on sale Friday. Collectors will be charged 44.99 pounds for each of the limited edition coins.
William Shakespeare, Winston Churchill, Charles Darwin and Florence Nightingale are among British luminaries whose images have graced special coins.
Lennon is seen with long hair and sideburns and his trademark round glasses.
The former Beatle would have been 70 this year.