There are four houses of Hogwarts. They compete yearly for the House Cup and are often on good terms with each other, aside from usual teenage drama and bullying.
The Good Guys
Harry Potter (Darren Criss)
Ron Weasley (Joey Richter)
Hermione Granger (Bonnie Gruesen)
Ginny Weasley (Jaime Lyn Beatty)
Neville Longbottom (Richard Campbell)
Dean Thomas (Britney Coleman)
Seamus Finnigan (Brian Rosenthal)
Lavender Brown (Ravenclaw in AVPM, Gryffindor in AVPS) (Sango Tajima)
Cedric Diggory (Tyler Brunsman)
Pansy Parkinson (Ravenclaw in AVPM, Hufflepuff in AVPS) (Lily Marks)
Unnamed Hufflepuff Student (Britney Coleman)
Unnamed Hufflepuff Student 2 (Lily Marks)
The non-Finders who are neither Good nor Bad.
Cho Chang (Devin Lytle)
Lavender Brown (Reassigned to Gryffindor in the Sequel) (Sango Tajima)
Pansy Parkinson (Slytherin in canon, reassigned to Hufflepuff in the Sequel) (Lily Marks)
Unnamed Ravenclaw Student (Arielle Goldman)
Luna Lovegood (Arielle Goldman)
The Bad Guys.
Draco Malfoy (Lauren Lopez)
Vincent Crabbe (Julia Albain)
Gregory Goyle (Jim Povolo)