Harry Potter is placed in Gryffindor by the Sorting Hat at Hogwarts.
The Sorting Hat makes its decision during the welcoming feast in Harry Potter and the Philosopher’s Stone. Harry briefly fears Slytherin, especially after learning about the house’s connection with Lord Voldemort, and silently asks the Hat not to place him there. The Hat announces Gryffindor instead.
Gryffindor is traditionally associated with courage, nerve, chivalry, and daring. Harry joins Ron Weasley and Hermione Granger in the house, and the trio’s adventures are closely tied to Gryffindor’s rivalry with Slytherin.
The Hat’s choice is not simply a measure of personality. The books show that a student’s wishes can matter, and that people may display qualities associated with more than one house. That is why Harry’s fear of Slytherin is an important part of the scene rather than evidence that he belongs there.