Here is a list of Harry Potter birthdays! (Not sure if these are accurate, I pulled them off a website. Also not sure what category this goes in so.)
January 9 = Severus Snape (1960)
January 26 = Gilderoy Lockhart (WW)
January 30 = Lily Potter (DH22) (1960)
February 6 = Arthur Weasley
February 13 = Luna Lovegood (JKR:Tw)
February 24 = Newt Scamander (WFT) (1897)
March 1 = Ron Weasley (1980)
March 9 = Sybill Trelawney (WW)
March 10 = Remus Lupin (1960)
March 27 = James Potter (1960)
April 1 = Fred and George Weasley (1978)
April ? = Teddy Lupin (1998)
April 28 = Horace Slughorn (WW)
May 2 = Victoire Weasley (YL)
May 15 = Pomona Sprout
June 5 = Draco Malfoy (BFT) (1980)
June 23 = Dudley Dursley (inferred from canon) (1980)
June 28 = Dobby
July 30 = Neville Longbottom (OP37, JKR) (1980)
July 31= Harry Potter (1980)
August 11 = Ginny Weasley (1981)
August 18 = Celestina Warbeck (WW)
August 19 = Tina Goldstein (WFT) (1901)
August 22 = Percy Weasley (1976)
August 26 = Dolores Umbridge (WW)
September 19 = Hermione Granger (1979)
September 25 = Garrick Ollivander (WW)
September 26 = Quirinus Quirrell (WW)
October 4 = Minerva McGonagall (1935)
October 17 = Filius Flitwick (JKR)
October ? (third week) = Angelina Johnson (GF16)
October 30 = Molly Weasley (c. 1950)
November 3 = Sirius Black
November 22 = Silvanus Kettleburn (WW)
November 29 = Bill Weasley (1970)
December 6 = Rubeus Hagrid (1928)
December 12 = Charlie Weasley (1972)
December 31 = Tom Marvolo Riddle (Lord Voldemort) (1926)