<p>Sandy Hawkins was still a kid in all his Golden Age appearances. His first post-Golden Age appearance was in <i>Justice League of America</i> #113 (1974), in which it was revealed that he had been imprisoned since the Golden Age. So I don't think he ever graduated from high school; maybe he never even attended. </p><p>Speedy was almost certainly out of high school by his heroin days in <i>Green Lantern</i> (Volume 2) #85 (1971). But he and the other Titans were all apparently in high school in 1966-1969, since their adventures at that time were high-school based, not college based (see <i>Teen Titans</i> #3, <i>Teen Titans</i> #16, <i>Teen Titans</i> #19). </p><p>Robin graduated high school in <i>Batman</i> #217 (1969). Kid Flash graduated high school, and revealed his secret identity to his parents, in <i>DC Special Series</i> #11 (1978). </p><p>The character I have in mind graduated before any of these. </p>

do flashbacks count?

<p>A flashback would count, as long as the character was a costumed hero/heroine in high school. So a flashback to Bruce Wayne's high school graduation doesn't count, not because it's a flashback, but because Bruce Wayne wasn't a costumed hero prior to graduating high school. </p><p>But whether or not it's a flashback, I'm looking for the first in <i>publication date</i>. For example, the Earth-Two Robin first appeared as an adult in <i>Justice League of America</i> #55 (August 1967). If his graduation had been mentioned or shown in a flashback in that issue (which it was not), then it would count as August 1967, even though theoretically that flashback might have taken place earlier than that. </p>

<p>Hint: This was in the Silver Age, and it's not a super-obscure character. </p>

<p>Kal-El as Superboy/Superman, Lana Lang </p>

<p>To the best of my knowledge, Clark Kent's high school graduation was not shown or mentioned in the 1960s or earlier. I'm sure, if asked, the writers would have said that Clark Kent did finish high school, but we only saw Superboy in his school days, and Superman in his adult days. (There's at least one story set a bit later than the usual Superboy stories -- <i>Superman</i> #161, in which Ma and Pa Kent died -- but this story never says whether Clark and Lana are still in school.) If someone can point to a Clark Kent graduation referenced earlier than the graduation of the hero/heroine I have in mind, then that would count as a correct answer. </p><p>The same applies to Lana Lang. </p>

Snapper Carr?

Nope.

Green Lantern?

Supergirl?