Harry is the recipient of this endearing ballad during Chamber of Secrets courtesy of Lockhart's Valentine's Day dwarves:
His eyes are as green as a fresh pickled toad,
His hair is as dark as a blackboard.
I wish he were mine, he's really divine,
The hero who conquered the Dark Lord.
(Chamber of Secrets, Chapter 13, The Very Secret Diary).
We know at this point that Ginny has the hots for Harry and so it's probably reasonable to assume that she sent the Valentine. I'm wondering if this was ever confirmed later in the story or by JKR-decree. After all, Harry was a very famous kid who was used to receiving a lot of popularity and attention due to his exploits on the Quidditch pitch. Perhaps it's not so unlikely that some other girl may have sent it. Malfoy, though, seemed to think it was Ginny.
Malfoy was looking furious, and as Ginny passed him to enter her classroom, he yelled spitefully after her, "I don't think Potter liked your Valentine much!"
Ginny covered her face with her hands and ran into class.
(Chamber of Secrets, Chapter 13, The Very Secret Diary).
Malfoy has his suspicions, as do I - but they're not exactly conclusive. Was it definitely Ginny?
