Bette Kane – Pre-Crisis “Bat-Girl” and niece of Kathy Kane a.k.a. Batwoman. Post-Crisis she is best known for her stint as Flamebird.
Barbara Gordon – Daughter of Gotham Police Commissioner James Gordon. Shot by the Joker, she became paralyzed and took of the mantle of “Oracle” becoming the leader of her own all-women team the Birds of Prey and the information expert for nearly every superhero in the DC Universe.
Helena Bertinelli – Had a brief stint as “Batgirl” temporarily filling in as the bat-themed hero of Gotham while Batman was MIA. She wore a full face mask and costume that would be passed down to Cassandra Cain. She eventually returned to her better known role as Huntress.
Cassandra Cain – Daughter of assassins David Cain and Lady Shiva, Cassandra left her father as a child after she killed a man. She initially did not speak often, communicating almost entirely via body language due to the way she was raised. Cassandra became the new Batgirl with Batman and Oracle’s blessing, and later took on the mantle of the Black Bat.
Stephanie Brown – Daughter of a low-ranking villain, Cluemaster, she took on the mantle of “Spoiler” to fight crime in the less affluent areas of Gotham ignored by the big bat and her own father’s plans. She became pregnant as a teenager, giving the child up for adoption, and when Tim Drake (Robin) gave up the mantle she temporarily became Robin before Cassandra Cain passed the Batgirl mantle on to her.
Charlotte Gage-Radcliffe – Having a very brief stint as Batgirl, Charlie is an orphan with teleportation powers who temporarily fought crime in Gotham as Batgirl (a couple of weeks during the year of Stephanie’s faked death) before being taken under the tutelage of Oracle and the Birds of Prey as Misfit.
Nell Little – When Stephanie returned to the Batgirl mantle after a year of faked death, Nell was a young Gothamite and Batgirl fan she ran into repeatedly. At the end of Stephanie’s pre-nu52 title run a glimpse of the future showed Nell as the Batgirl to Stephanie’s Nightwing.
Tiffany Fox – Daughter of Wayne Enterprises CEO/President Lucius Fox, Tiffany appears as the newest and youngest Batgirl in the nu52 Future’s End story arc.
Nissa – The Batgirl of Neo-Gotham in the future-set Batman Beyond universe.