The title says it all, my question is, has JK Rowling ever commented on why she chose the name Harry for her main character?
She just really liked the name. Rowling was asked this question in a 2000 live interview on Scholastic.com; her response was:
Question: From where did you get the name for Harry Potter?
Rowling: 'Harry' has always been my favourite boy's name, so if my daughter had been a son, he would have been Harry Rowling. Then I would have had to choose a different name for "Harry" in the books, because it would have been too cruel to name him after my own son. "Potter" was the surname of a family who used to live near me when I was seven years old and I always liked the name, so I borrowed it.
There is a character named Harry Potter in the 1986 film "Troll", which some people claim is where JK Rowling got the name from originally.
Director John Buechler claimed that he invented Harry Potter:
His producer partner Peter Davy said, “In John's opinion, he created the first Harry Potter. J.K. Rowling says the idea just came to her. John doesn't think so. There are a lot of similarities between the theme of her books and the original Troll. John was shocked when she came out with Harry Potter."
And producer Charles Band said in an interview that JKR may have been inspired by this film:
It's bizarre, isn't it? You have a young boy named Harry Potter who discovers that he has magical powers and uses them to fight a troll.
"I've heard that JK Rowling has acknowledged that maybe she saw this low-budget movie and perhaps it inspired her. Who knows what the story is? Life's too short for a fight as far as I'm concerned but, having said that, there are certain scenes in that movie, not to mention the name of the main character, and this of course predates the Harry Potter books by many, many years. So there's that strange connection."
This answer is community wiki as it was a joint effort between K H (who posted this minimal now-deleted answer) and myself (I researched and found the above quotes after K H put me on to this film). Originally I edited K H's answer instead of posting a new one, but my edit was rolled back and the post deleted, so I've put the information here instead.