| Issue | #334 |
| Published | March 1966 |
| Cover Price | 0.25 USD |
| Pages | 80 |
| Editing | Mort Weisinger |
| Notes | On Sale Date - January 18th 1966 also 80 Page Giant #G-20 |
| Genre | superhero |
| Pencils | Curt Swan |
| Inks | Sheldon Moldoff |
| Notes | also 80 Page Giant #G-20 |
| Characters | Superman [Kal-El; Clark Kent]; Supergirl [Kara Zor-El] (introduction, first appearance, origin); Zor-El (introduction); Miss Hart (introduction) |
| Synopsis | Superman spies a crashing rocket and discovers his cousin Supergirl. She tells him how Argo City survived the destruction of Krypton and how her father sent her to Earth when the inhabitants of Argo City were threatened by Kryptonite poisoning. Superman sets her up in Midvale Orphanage so she can adjust to life on Earth. |
| Genre | superhero |
| Script | Otto Binder |
| Pencils | Al Plastino |
| Inks | Al Plastino |
| Editing | Mort Weisinger (original) |
| Reprinted | from Action Comics (DC, 1938 series) #252 (May 1959) |
| Genre | Superhero |
| Letters | Typeset |
| Notes | Describes meeting before Supergirl's existence revealed. |
| Genre | superhero |
| Script | Otto Binder |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Reprinted | From Action Comics (DC, 1938 series) #259 (December 1959) |
| Characters | Supergirl; Jerro the Merboy (first appearance) |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Reprinted | from Action Comics (DC, 1938 series) #269 (October 1960) |
| Characters | Supergirl; Streaky (first appearance) |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Reprinted | from Action Comics (DC, 1938 series) #261 (February 1960) |
| Genre | Super-Hero |
| Characters | Supergirl |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Reprinted | from Action Comics (DC, 1938 series) #271 (December 1960) |
| Characters | GS: Legion of Super-Heroes (Cosmic Boy, Lightning Lad, Saturn Girl, Chameleon Boy (1st), Colossal Boy (1st), Invisible Kid (1st)); Superman app. |
| Synopsis | Supergirl invited to 30th Century to join Legion; rejected |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Letters | Joe Letterese |
| Notes | original pages 2-3 cut; 3rd app Legion of Super Heroes |
| Reprinted | fr. Action #267 (Aug '60) |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Curt Swan |
| Inks | John Forte |
| Notes | 1 page cut. Writer credit confirmed from Martin O'Hearn. Ink credit confirmed from Pat Lang & Bob Hughes. |
| Reprinted | From Superboy #80 (April 1960). |
| Characters | Superman; Supergirl |
| Genre | superhero |
| Script | Jerry Siegel |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Notes | single page excerpt |
| Reprinted | From Action Comics (DC 1938 series) #285 (Feb 1962) |
| Characters | Supergirl; Comet |
| Genre | superhero |
| Script | Leo Dorfman |
| Pencils | Jim Mooney |
| Inks | Jim Mooney |
| Notes | this is not the 1st appearance of Comet, see Adventure Comics 293, Feb 1962 |
| Reprinted | from Action Comics (DC, 1938 series) #292 (September 1962) |
| Letters | typeset |