Many late 70s examples for me also…not sure exactly who was first…
Tia from Escape to Witch Mountain
Jana of the Jungle from Electric Company
Isis from the Shazam/Isis power hour
Valerie Bertinelli from One Day at a Time
She once ‘liked’ one of my Tweets. Made me very happy for a few days.
I much preferred her with the longer hair-when she cut it and went all coiffed she kind of lost me.
A colleague of my physician father’s had 2 daughters who very closely resembled both her and Mackenzie Phillips-yes I was a bit attracted to the one who looked like VB…
Totes adorbs. Did you know she also cowrote, with her husband, a not-very-good Star Trek episode?
That’s not Turnabout Intruder bad, but I definitely lost a boatload of respect for Scotty in that episode.
I knew, but decided not to mention it out of respect for Shari.
I did not know that. But most folks probably don’t know that Shari started out as a talented professional dancer, so I’m willing to forgive her for not exactly being Isaac Asimov when it came to science fiction.
Yeah, and I never heard of Asimov being a professional dancer!
True, but I believe his unpublished sequel was I, Robot Dancer.
How do you feel about Kathy Keeton?
Idk - how was she with hand puppets?
In 5th grade I think I fell in love with Harriet the Spy (book; movie came eons later). I thought she was amazing and unstoppable but she was also vulnerable and I wanted to take care of her when everyone read her journal without permission and all her friends turned against her.
There was a girl in my high school homeroom who was a dead ringer for Susan Dey. I spent half of my Freshman year lusting after her.
There’s a episode of The Partridge Family in which Susan and Shirley Jones are modeling their new hot pants costumes in front of a wall of mirrors. That one scene was enough to light my rockets, yessiree! 
Yeah it’s kind of hard to pinpoint when I started to get “funny feelings” about characters I used to see on TV as a kid.
Also hard trying to separate out actual “crushes” vs just noticing attractive female characters.
And do I make a separate category for actual “age appropriate” vs “older women” crushes and “cartoon crushes”?
Nah. You might get confused with whichever fetish they put in that particular episode. The show is widely known to do so, with people wondering if it could possibly not be intentional.
I was almost too embarrassed to post…
My first fictional crush was Egon Spengler, from the Ghostbusters cartoon.
I was also very fond of Luigi (yes, of the Mario brothers).
I still tend to find certain (adult!) cartoon and video game characters to be attractive.