When Veronica first appeared in the episode, A Wish Too Far, she seemed to dislike Timmy. However, in the episode Information Stupor Highway, Timmy overhears her state that her love for him "burns with the white hot intensity of a thousand suns." To which Timmy said, "Great, the crazy one likes me." It was also implied in Mind Over Magic that she still desires Timmy, as when Timmy read her mind, he heard her think "Why isn't this loser talking to me?". From what Timmy says in Information Stupor Highway, he doesn't seem to be attracted to her and thinks she is nuts. Timmy does not particularly like this because his real crush is Trixie Tang.
There are some fanfiction that involve a Veronica /Timmy pairing. However, Veronica herself has not appeared very much and has had no major speaking roles since "You Doo" and beyond.
- Information Stupor Highway - Episode where this crush is first established.
- Mind Over Magic - A possible hint toward this pairing when Veronica becomes jealous of Timmy paying more attention to Trixie.
- 77 Secrets of The Fairly OddParents Revealed! - Veronica's crush is mentioned on Timmy's character card.