Sonic's birthday

Sonic's Birthday is the date of his birth. Despite him being without parents, it is widely believed his date of birth is the same as the anniversary of his first game Sonic the Hedgehog which was released (June 23, 1991) however Sonic's canon age is 15 years old while his game series is 20 years old.

In the games
At the start of Sonic Generations Tails and friends throw a suprise Birthday party for Sonic, before it gets interrupted by the Time Eater.

How old Sonic was is never specified during the event.

Adventures of Sonic the Hedgehog


Sonic has a Birthday in this series. While Sonic and Tails are vagabonds, Sonic still remembered his birthday despite lacking memory of his parents or a calender to keep track of his birth.

For a gift Tails builds Sonic an interesting gift. Realizing Tails' potential with mechanics, Sonic asks Professor Von Shlemmer to make Tails his research assistant, but then Robotnik captures and impersonates him to get Tails to build his latest anti-Sonic weapon.

Sonic Underground
Sonic shares his birthdate with his singlings Sonia and Manic. they were all born on March 4. this is coincidentally the same date when the portal to Mobodoon opens every 4 years.