All of the characters who attend Ravenclaws for being intelligent and creative.
Though the sorting hat decides which house to place each individual in, most characters have traits from more than one house. Dumbledore is one of these characters, with many aspects of his personality fitting in both Slytherin and Gryffindor's house. Here are some reasons why Dumbledore could have been sorted into Slytherin House and some reasons Gryffindor is the perfect place for him!
Slytherin: Strong-Leader
One trait that is associated with Slytherin house is strong leadership. There is no denying that this is a trait that Dumbledore possesses. He shows excellent leadership through his position as heaster at Hogwarts. He also helps lead the resistance against Voldemort as the founder and a crucial member of the Order of the Phoenix.
Dumbledore mentors Harry, doing his best to protect Harry and prepare him for the impending showdown between him and Voldemort. Without Dumbledore's leadership, the battle against Voldemort likely wouldn't have been won.
Gryffindor: Bravery
Dumbledore confronts difficult situations head-on. This is demonstrated through his forcefulness when standing up to Umbridge and Dumbledore's plan to have Snape murder him. He doesn't let fear stop him as he continues to push forward.
Dumbledore also makes it very clear that he values bravery. When Harry and his friends violate school rules, resulting in heroic accomplishments, Dumbledore is quick to reward them for their bravery. Gryffindors are known for not only possessing bravery but for valuing bravery, which is clearly demonstrated by Dumbledore.
Slytherin: Ambitious
Dumbledore is an ambitious person. Once he sets his mind to accomplishing something, he refuses to back down. Dumbledore works his way up in the wizarding world. He begins working as a professor at Hogwarts and then transitions into a role as a department head.
Eventually, he works his way up to being the heaster of the school. Dumbledore's ambition gains him respect and fame within the wizarding world.
Gryffindor: Chivalry
Dumbledore believes in justice and honor. He is always ready to act to help protect and defend those who need assistance. Dumbledore respects those around him and is quick to acknowledge others for their strengths, including the students at Hogwarts.
Dumbledore has core values which he is unwilling to compromise. He is even willing to go against his close friend, Grindelwald when he feels Grindelwald is crossing the line. Dumbledore is committed to taking down Voldemort at all costs and this stems from his desire to help marginalized individuals.
Slytherin: Resourcefulness
Slytherins are extremely resourceful, and this is a trait that Dumbledore possesses as well. Dumbledore has been in plenty of situations where he has to be creative and use what he has available to him.
He recognizes the importance of thinking on one's feet and being creative in difficult situations. Dumbledore even attempts to this lesson on to Harry, recognizing the value this skill will have.
Gryffindor: Bold
Dumbledore is incredibly bold. He speaks his mind, standing up to the Ministry and Umbridge. Dumbledore is unswayed by the opinions of those around him, acting on what he knows is right.
He is quick to hire Hagrid despite the pushback he receives for this decision. Dumbledore remains calm and confident, leaving no room for others to question his decisions.
Slytherin: Cunning
Not all of Dumbledore's plans were well-formulated, but he did make a number of plans that were incredibly cunning. One example is Dumbledore's idea to use the Mirror of Erised to conceal the Sorcerer's Stone. He knew that by doing this, the stone would only be obtained by someone who wasn't interested in using the stone for their own gain.
Another example of Dumbledore's cunning ability was his plan to have Snape kill him. Dumbledore already knew he was dying and made the difficult decision to create a plan that would help on multiple levels. By doing so, he protected Draco and secured Snape's undercover identity, allowing him to continue working as a double agent.
Gryffindor: Willing To Sacrifice
One of the main reasons Dumbledore belongs in Gryffindor and not Slytherin is because he is willing to sacrifice himself for others. Dumbledore fatally injured himself hunting down Horcruxes and even this did not deter him from his fight against Voldemort. It is clear that defeating Voldemort is a cause for which Dumbledore is willing to die.
Dumbledore also takes the blame for other characters. When the Chamber of Secrets is open, Dumbledore is quick to step down. This is partially to distract from the blame that is being placed on Hagrid. This willingness to accept responsibility for the action of others is present throughout the entire series and goes against the core value of self-preservation that most Slytherins possess.
Slytherin: Shrewd
Dumbledore is remarkably good at reading others. His ability to accurately judge the character of others allows him to catch on when something is off with Tom Riddle, Slughorn, and Harry Potter. Similarly, Dumbledore often correctly deems people as trustworthy when others are quick to dismiss them.
This is the case with his relationships with Hagrid and Snape. This trait was a crucial aspect of Dumbledore's character and is often associated with Slytherin house.
Gryffindor: Noble
Dumbledore is not motivated by fame or power. He does not care about being ed or leaving a legacy. Instead, Dumbledore does the right thing simply because it is the right thing to do. He wants to do good and remains consistent in his beliefs regardless of who is watching.
While many Slytherins are motivated by acclaim, Dumbledore's motivations are more in line with those of Gryffindors.