I've been trying to locate from where certain Harry Potter characters come from in Britain (as in Scotland, Wales, England and Northern Ireland), and have had limited success. Most of these characters are involved in the main storyline.
Note: Since it's a long list of characters, I understand if no answer contains all the characters' locations. Plus, to make things easier, I've struck out the names of the characters whose origins I have found, either through my research or through the answers below.
Harry James PotterHermione Jean GrangerThe WeasleysDean Thomas
Seamus FinniganCedric DiggoryErnie Macmillan
Justin Finch-Fletchley
Hannah Abbot
Marcus Flint
Cho Chang
Parvati and Padma Patil
Draco MalfoyLavender Brown
Oliver Wood
Minerva McGonagallFilius Flitwick
Severus SnapePomona Sprout
Horace E.F. Slughorn
What I've found
I've located the following characters:
McGonagall: Scotland
The Weasleys: England (Devonshire)
Harry Potter: England (Surrey)
Remus Lupin : Wales (ancestry)
Hermione: England (London)
Luna Lovegood: England (Devon)
What I need
The locations from where the other characters are from, or are strongly associated with (e.g. Harry might not originally be from Surrey, but has lived there long enough to be associated with it).
Of course, it might be very hard to find actual references to their locations (it was for me), so I'll accept an answer if it provides sound reasoning for a claim despite there not being any direct evidence for it.
For example(not an actual claim), if an answer claims Seamus is Irish based on his mannerisms, language, etc. I'll accept it, provided the reasoning is sound.
I also make a rare exception in accepting information from Harry Potter Wiki and other such "non-canon" sources provided the answer is reasonable.
Feel free to add your thoughts in the comments.