What follows is a hopefully alphabetical listing of every character that is currently embroiled in one or more romances, and who they are linked to romantically. Listings will overlap.
If you don't see a person's name, odds are they're single.
20th CENTURY:
Animal Man - Is married to Ellen Baker, and has two children with her. Also has a daughter with Annie Cassidy.
Argent - Is dating Kid Emotion.
Aquaman - Is married, but estranged to, Queen Mera. Is infatuated with Wonder Woman (Diana)
Batgirl - Is dating Green Arrow (Ollie)
Captain Marvel - Has dated Argent and Shadowcat but remains single.
Catwoman - Is the occasional suitor of Wildcat.
Dolphin - Is married to Tempest and the mother of his child.
Elongated Man - Is married to Sue Dibny.
Firestorm - Is dating Zatanna Zatara, and is the father of her child.
Flash (Jay) - Is married to Joan Garrick.
Flash (Wally) - Is married to Linda Park.
Geo Force - Is engaged to marry long-time girlfriend, Denise.
Green Arrow (Ollie) - Is dating Batgirl. Has sired numerous illegitimate children.
Green Lantern (Alan Scott) -- Former husband of Alyx Thorin/Rose Canton (The Thorn). Husband of Molly Mayne Scott (The Harlequin).
Green Lantern (Jade) - Engaged to Green Lantern (Kyle), and is pregnant with his child. Daughter of Green Lantern (Alan Scott) and the Thorn.
Green Lantern (Kyle) -- Engaged to Green Lantern (Jade), who is pregnant with his child.
Halo - Believes, wrongly, that she is still in a relationship with former team mate Faust.
Hawkman (Charles) - Was dating the now deceased Aquagirl II. Is currently single.
Hero I - Is gay and single.
HERO II (Croyd) - Is straight and single. Infatuated with Huntress.
Hourman - Rex Tyler's soul within the android believes himself to be still married.
Impulse - Is undecided about his sexuality and relationships in general.
Jack O'Lantern - Is bisexual and single.
Jesse Quick - Is the wife of Nightwing, and the mother of his children. Is also the "mother" of Nightstrike.
Johnny Quick II - Is dating Liberty Belle III of the clones A.S.S. Is and is not the same Johnny who sired Jesse Quick.
Karate Kid - Married to Queen Projectra of Orondo, whom he long thought dead. Seeing Superwoman, the mother of his son.
Kid Emotion - Is dating Argent
Liberty Belle III - Is dating Johnny Quick II of the clones A.S.S. Is and is not the same Libby who birthed Jesse Quick.
among the Metal Men, Platinum and Veridium are in a relationship.
Mirage - Is the mother of one of Nightwing's children.
Mister Miracle - Is a widower due to Barda's death.
Mockingbird - Is married to Arsenal. She is also pregnant with his child.
Nightstrike - Was dating Redbird/Nightbird. Is the son of Jesse Quick and Nightwing from a possibly alternate future.
Nightwing - Is married to Jesse Quick and the father of her children. Is also the "father" of Nightstrike.
Obsidian - Is gay, insane and single. He is the son of Green Lantern (Alan Scott) and the Thorn.
Pied Piper - Is gay and in a relationship.
Red Tornado - Is married to Kathy Sutton, and has an adopted daughter, Traya, with Kathy.
Robin (Stephanie) - is dating Robin (Tim) and is the daughter of the villain Cluemaster.
Robin (Tim) - Is dating Robin (Stephanie).
Secret - Is dating Valor.
Shockwave - Dates Terra occasionally.
Snow - Is the widow of Mr. Freeze.
Starfire - Is from a parallel universe where she was married to that universe's Nightwing, who is also the father of her child.
Starman (Jack Knight) - Is dating Sadie Payton. Has a son with his arch-nemesis the Mist, and a daughter on the way with Sadie.
Starshine - Is a lesbian and single.
S.T.R.I.P.E. - Is married to Star Spangled Kid's mother.
Superboy (Kon-El) - Is persuing a relationship with Supervixen.
Supervixen - Occasionally dates Superboy (Kon-El).
Superwoman - Is dating Karate Kid, who is the father of her son. Continues to be the object of Brainiac 5.2's affections as well.
Tempest - Is married to Dolphin and the father of her child.
Terra - Dates Shockwave occasionally.
Twilight - Is gay and single.
Valor - Is dating Secret.
Wildcat - Is the occasional suitor of Catwoman.
Wondergirl - Has a child from seemingly immaculate conception, she gave the child up to the Amazons for adoption. She continues to harbor desires for more than friendship from Superboy (Kon-El).
Wonder Woman (Diana) - Is a lesbian and single.
Wonder Woman (Donna) - Is a widow.
Zatanna - Is dating Firestorm and is the mother of his child.
LEGION ERA:
Andromeda - Is in a relationship with Green Lantern (Rond) and the mother of his child. She still has romantic feelings towards Brainiac 5.2, and might be bisexual.
Blok - Is infatuated with the White Witch.
Brainiac 5.2 - Is single though he continues to harbor romantic obsessions with both Superwoman and Andromeda.
Chameleon Boy - Is unsure of what his/her/its sexual identity is.
Collossal Boy - Is married to Yera.
Dawnstar - Is in love with Wildfire.
Dreamer - Is single but has been romantically linked to Starman (Thom) and Rebound.
Element Lad - Is engaged to marry SP Officer Schvaugn Erin.
Green Lantern (Rond) - Is in a relationship with Andromeda and is the father of her child.
Immortal Lad - Is gay and single. He approaches relationships with women, however, out of his Princely duty to Rann to acquire a harem of fertile wives.
Invisible Kid - Is gay and single.
Karate Kid (Val) - Married to Queen Projectra of Orondo, whom he long thought dead. Seeing Superwoman, the mother of his son.
Kid Flash - Is dating Pandora.
Lightning Lad - Is the widower of Saturn Girl, who was the mother of his twin sons.
Lightning Lass - Is bisexual and has been in relationships with Timberwolf and Shrinking Violet.
Pandora - Is dating Kid Flash.
Phantom Girl - Is married to Ultra Boy and is the mother of his children.
Queen Projectra - Is married to Karate Kid (Val).
Rebound - Is dating Thunder, who is under-age in her natural form. In the past he has been romantically linked to Triad, Shrinking Violet and Dreamer.
Shrinking Violet - Is bisexual and has been in relationships with Duplicate Boy, Rebound and Lightning Lass, but is currently single.
Sun Boy - Is an unabashed womanizer.
Superboy (Kal-El) - Still harbors long-term crush on Phantom Girl.
Superboy (Kon-El) - Is persuing a relationship with Supervixen.
Superwoman - Is dating Karate Kid, who is the father of her son. Continues to be the object of Brainiac 5.2's affections as well.
Thunder - Is dating Rebound.
Timberwolf - Is still pining over Lightning Lass.
Ultra Boy - Is married to Phantom Girl and is the father of her children.
Wildfire - Is in love with Dawnstar.
Yera Allon - Is married to Collossal Boy.