Gryffindor corresponds roughly to the element of fire, and it is for that reason that the colours scarlet and gold were chosen to represent the House. The colour of fire corresponds to that of a lion as well, with scarlet representing the mane and tail and gold representing the coat.
The Gryffindor house emphasises the traits of courage as well as "daring, nerve, and chivalry," and thus its members are generally regarded as brave, though sometimes to the point of recklessness. They can also be short-tempered. Notably, Gryffindor house contributed many members to Dumbledore's Army and the Order of the Phoenix, although this may have been because the main members made it a point not to associate with other houses.
According to Phineas Nigellus Black, members of other houses, particularly Slytherin, sometimes feel that Gryffindors engage in "pointless heroics." Another Slytherin, Severus Snape, considered many Gryffindors to be self-righteous and arrogant, with no regard for rules.
"The House of Godric Gryffindor has commanded the respect of the wizarding world for nearly ten centuries."
Gryffindors and Slytherins have shared a fierce house rivalry since their founders, Godric Gryffindor and Salazar Slytherin, respectively, had a severe falling out over Slytherin's emphasis on blood purity which Gryffindor felt was wrong. There might also be an element of feeling wronged, as Harry and his fellow Gryffindors tend to win in a lot of circumstances which, when viewed from a neutral point of view, may be considered unfair. Examples of this include the last-minute points awarded by Headmaster Dumbledore at the Leaving Feast, which conveniently put Gryffindor ten points ahead of Slytherin in the 1991–1992 school year, the fact that no points were deducted for the rule breaking that happened during that night and Harry being permitted by Professor McGonagall to have his own broomstick for the Gryffindor Quidditch team, even though first-years are not normally permitted their own broomsticks because of danger.
Overall, however, the houses of Ravenclaw and Hufflepuff tended to side with Gryffindor in its rivalry with Slytherin. This was particularly notable during the Second Wizarding War — the members of Dumbledore's Army were from Gryffindor, Hufflepuff, and Ravenclaw, but the Army lacked any Slytherins. (This, however, could also have been because news of Dumbledore's Army was passed by word of mouth, and Harry, who had initially raised it, did not associate with any Slytherins.) During the Battle of Hogwarts, the Slytherin students left, while senior students from the other three houses remained behind to fight against Lord Voldemort and his army - however, it is also worth nothing that while Head of House Professor Slughorn left with his students, he then returned to the castle with reinforcements (possibly including senior students) and with Professor McGonagall and Auror Kingsley Shacklebolt, personally duelled Lord Voldemort. Most of the known Death Eaters (besides Peter Pettigrew, Quirinus Quirrell, and possibly others) have been Slytherin House members, and that might have been another reason as to why the other two houses sided with Gryffindor over Slytherin.
The Gryffindor Common Room is located in one of the castle's towers (Gryffindor Tower), the entrance to which is located on the seventh floor and is guarded by an oil painting of the Fat Lady, who is garbed in a pink silk dress. She permits entry only after being given the correct (regularly changing) password. Behind her painting is a large common room, with a fireplace, and two staircases leading up to the girls' and boys' dormitories.
There is a spell on the girls' staircase that prevents boys from using it; however, there is no such enchantment on the staircase to the boys' dormitory, allowing girls to use it whenever they wish, due to the founders' belief that girls were more trustworthy. The common room is very comfortable, and members of the Gryffindor house meet there for study groups, celebrations, or relaxation. The walls are lined with portraits, each one depicting a previous or current Head of Gryffindor.
Knight and courtier in Henry VII's royal court, who was improperly beheaded for a magical attempt to straighten a lady-in-waiting's crooked teeth which instead made her grow a tusk. Later became the house ghost.
The third child and only daughter of the famous Harry Potter.
Behind the scenes
J.K. Rowling was once asked in an interview into which House would she sort British politician and former Prime minister Gordon Brown, were she the Sorting Hat. She jokingly responded that she would sort him into Gryffindor, because of the red colours of his political party, which match the colours of Gryffindor.
Rowling herself was sorted into Gryffindor House on Pottermore.
Rubeus Hagrid stated in the first book that all the wizards who went bad were from Slytherin, however, Peter Pettigrew, who was in Gryffindor disproves this. At this point, Hagrid was unaware that Pettigrew was still alive, or that he was working for Voldemort. (It should also be noted that Quirinus Quirrell, a Ravenclaw, was working for Voldemort at the time, although Hagrid was unaware of this as well.) Another reason why this is odd is that, at the time, Sirius Black was believed to have gone bad (Hagrid's comments in the Three Broomsticks prove that he knew nothing of the truth in this instance), and he was also a Gryffindor. So Hagrid would have known of at least one Gryffindor who had 'gone bad'. He most likely did not mention this so that Harry would not try to find out more about his godfather, or it could have been 'Gryffindor propaganda' since Slytherin and Gryffindor are known rivals. It is also possible that Hagrid did not remember these exceptions at the time.
Bonnie Wright, the actress who portrayed Ginny Weasley in the films, was sorted into Gryffindor house on Pottermore.
Tom Felton, the actor who portrayed Draco Malfoy in the films, was sorted into Gryffindor house on Pottermore.
It should be noted that the colours and emblems of Gryffindor resemble the historical English coat of arms. Whether this was intentional on Rowling's part is unknown.
Gryffindor House won the second House Cup in Pottermore; their reward for winning was Gryffindor-related downloadable material.
The Sorting Hat considered placing Filius Flitwick in Gryffindor before choosing Ravenclaw.
Gryffindor's entrance changed locations once throughout the film series. In the first film, the students go down a long hallway to reach the entrance portrait. In the third film, the portrait is located very close to the Grand Staircase. It can only be assumed that this is its location for the rest of the series as the outside of the entrance would not be seen again for the rest of the film series.
Pottermore House Cup
Gryffindor came second for the first house cup with 74,069,919 house points.
Gryffindor won the second house cup with 48,538,348 points.
Gryffindor came third for the third and fourth house cups with 26,740,444 and 24,610,105 points.
Gryffindor came fourth for the fifth house cup with 27,299,570 points.
Gryffindor came second for the sixth house cup with 32,279,991 points.
Gryffindor came fourth for the seventh and eighth house cups with 49,335,378 points.
Gryffindor could possibly be derived from griffin, which is a creature in mythology with the body of a lion and the head of an eagle.
In Old English and Old High German dor means gate or door.
In French "d'or" means "of gold," one of the Gryffindor House colours, though it can also come from the Greek word "dora" meaning "gift".
A combination can be assumed; "Golden Gift of the Lion".
"Griffe" is the French word for "claw", which could refer to the claw of the lion.
"Gryffindor" could very well be explained by heraldry: "Gryffin" would then stand for the griffin beast, and the "[d]or" would refer to the metal tincture "[d'] or" (Middle English for "[of] gold", derived from French; corresponds to yellow).
Gryffindor is also a pun on the golden gryffin, which is a lion that only has eagle wings, so it has the head and front paws of a lion, and has golden fur and feathers. Even the French for Griffindor, Griffondor is a French homophone for the actual beast, Griffon d'Or.