Matches Malone, as CandidGamera noted upthread.
As Candid also mentioned, the Martian Manhunter also had dozens of civilian identities all over the world; the majority were compromised when the government got hold of his journals, but he managed to keep some secret.
–Cliffy
Matt Murdock used to disguise hmself as his own swinging “brother”, apparently just for kicks.
Time Drake (Robin) has used “Alvin Draper” as his juvenile deliquent answer to Matches Malone.
Dr. Occult is actually a married coupled (the other half being Rose Psychic) who share the same time and space, and thus can never appear both at once.
Rebis of the Doom Patrol is another composite entity.
Not quite what you were asking for, but Aquaman is known in Atlantis as “Orin”, to the dolphins that raised him through early childhood as “Swimmer”, and to the lighthouse keeper that introduced him to human society, and thus to most other surface humans, as “Arthur Curry”. He’ll answer to all four.
Not a comic per se, but in Wildcards, Mister Gravemold / Mister Wallwalker were the same person (IIRC) and even had a ‘civilian’ identity, and, a ‘superhero’ identity that I don’t remember having a name. As Gravemold / Wallwalker, he would use different minor aspects of his power (the ability to negate any type of energy) to make people think he was just a ‘deuce’ (someone with a semi-useless superpower).
Christopher Chance, the Human Target, has taken on the identities of so many other people that he’s in constant danger of losing his own sense of self.
In The Watchmen, Night Owl and the new Silk Spectre show up at the end in new identities.
Throughout his “Silver age” run, Aquaman didn’t generally use even one secret identity, but in an issue of JLA he showed up briefly as “C. King” in a dockside bar, dressed as a sailor and obviously trying hard not to look like the King of Atlantis. It’s not exactly subtle. Maybe this is why he didn’t use the identity very often.
Thor has had human identities as both Dr. Donald Blake and Jake Olson.
Classic Superman has three distinct identities: Kal-El of the House of El of Krypton; his Earth ethnicity as midwestern reporter Clark Kent; and American icon superhero Superman, who was formerly Superboy. His is not merely a dual identity at all, but rather a treble. (In addition to his occassional adventures as Flamebird.)
J’onn J’onzz, as a shapeshifter, holds an array of Earthly secret identities which he considers crafted ‘art forms’ in order to both better understand and assimilate with humanity.
It was Ronnie Raymond and the other guy was Martin Stein.
I can’t beleive all this talk of multiple personalities and no Crazy Jane of the Doom Patrol.
She had at least, Jane, Driver 8, Flit, Mama Penticost and Black Annis. These are just what I can think of off hand.
At least once, Aquaman went undercover using the name “C. King.”
Psst, Reality Chuck, look up four entries.
She doesn’t fit the parameters of the OP in that she does not have multiple civilian identites, otherwise I would have listed her.
Her other personalities I remamber included Butterfly Baby, Scarlet Harlot (who IIRC eventually integrated) and The Lady in Purple. She initially had 64 I think, each with its own unique power. Most didn’t emerge in the course of her time in the series but a “map” of her personalities was seen in the same issue that introduced Driver 8.
Wasn’t the Flaming Carrot…
No, I guess he wasn’t
…nobody reads the daily strips? Since a bit before OP there’s been an ongoing plot in the daily Spiderman strips about a hospitalized Peter Parker fighting crime as “Gown Man”.