Action Comics

Superman

Clark Kent / Kal-El / Kal-L

Lois Lane

girlfriend/wife of Superman

Lex Luthor

Superman's arch-enemy

Jimmy Olsen

Superman's pal

Jonathan Kent

adoptive father of Clark Kent

Martha Kent

adoptive mother of Clark Kent

Lana Lang

from Superman

Krypto

Superboy's Super-Dog

Mr. Mxyzptlk

Superman villain, Silver Age / Modern Age

Garth Ranzz

Lightning Lad / Live Wire

Lightning Man

Garth Ranzz: Adult Legion timeline

Saturn Woman

Imra Ardeen-Ranzz: Adult Legion timeline

Dr. Xadu

Kryptonian

Gsptlsnz

girlfriend/wife of Mxyzptlk

Susie Tompkins

Lois Lane's niece

Glen Glenmorgan

from Superman

Kryptonite Man

Clay Ramsay