The Headmaster's Office

• Type: Office, Study, Residence
• Location: A tower in Hogwarts Castle, Scotland
• Owner/Residents: The current Headmaster or Headmistress of Hogwarts. Notable occupants include Albus Dumbledore, Armando Dippet, Dolores Umbridge, Severus Snape, and Minerva McGonagall.
• Key Features: Large circular room, guarded entrance requiring a password, walls lined with the portraits of former Headmasters and Headmistresses, contains numerous magical instruments, the Sorting Hat, the Sword of Gryffindor, and the Pensieve.

The Headmaster's office is a large, beautiful circular room located within a tower of Hogwarts Castle. Its walls are lined with portraits of all the previous Headmasters and Headmistresses of the school, who are known to sleep, snore, and offer counsel to the current Headmaster and each other. The room has several tall, arched windows that look out over the Hogwarts grounds towards the mountains. The office is filled with numerous spindly-legged tables upon which sit a variety of “delicate silver instruments” that whir, puff smoke, and hum. The purpose of these devices is largely unknown, though Albus Dumbledore implied they tracked various magical phenomena. Key objects of immense importance are also stored here, including the Sorting Hat, the Sword of Gryffindor (kept in a glass case), and Dumbledore's stone Pensieve, which he kept in a dark cupboard. A golden perch beside the desk was home to Fawkes, Dumbledore's phoenix. Access to the office is magically protected. The entrance is a single, polished oak door with a griffin-shaped knocker, located at the top of a concealed, moving spiral staircase. This staircase is hidden behind a large and rather ugly stone gargoyle in a corridor. The gargoyle will only spring aside to reveal the staircase when given the correct password. Under Dumbledore, these passwords were invariably the names of his favourite Muggle sweets, such as “Sherbet Lemon,” “Cockroach Cluster,” and “Fizzing Whizzbee.” The office itself is magically sealed and will resist entry or full control by anyone it deems unworthy of the post, as demonstrated when Dolores Umbridge was unable to open Dumbledore's desk or remove the Sword of Gryffindor from its case. Following Dumbledore's death, his portrait was magically added to the collection on the wall, appearing behind the Headmaster's desk.

The Headmaster's office serves as a crucial setting for revelations, counsel, and pivotal plot developments throughout the series.

• Harry Potter and the Chamber of Secrets: Harry Potter's first visit is after crashing the Ford Anglia. Here, he meets Fawkes and discovers that the Sorting Hat can produce the Sword of Gryffindor. After defeating the basilisk, Dumbledore uses the office to explain the nature of Tom Riddle's diary and why Harry possesses some of Voldemort's abilities.
• Harry Potter and the Goblet of Fire: After his name emerges from the Goblet of Fire, Harry is brought to the office. While waiting for Dumbledore, he discovers the Pensieve and views Dumbledore's memories of the trials of several Death Eaters.
• Harry Potter and the Order of the Phoenix: The office becomes a place of tension and distance between Harry and Dumbledore. It is later commandeered by Dolores Umbridge, though she never gains full command of its magic. The story's climax unfolds here, as Dumbledore reveals the full contents of the prophecy to a grief-stricken Harry.
• Harry Potter and the Half-Blood Prince: Harry and Dumbledore hold their private lessons in the office, using the Pensieve to explore Voldemort's history and the secret of his Horcruxes. After Dumbledore's death, a large portrait of him appears here, and Minerva McGonagall uses the room as a base of operations.
• Harry Potter and the Deathly Hallows: As Headmaster, Severus Snape uses the office, where he secretly communicates with Dumbledore's portrait to aid Harry's quest. In the aftermath of the Battle of Hogwarts, Harry returns to the office to use the Pensieve to view Snape's memories. He then has a final, clarifying conversation with Dumbledore's portrait about the Deathly Hallows and his own destiny, before using the Elder Wand to repair his original holly and phoenix feather wand.

• Gargoyle Corridor: The entrance is guarded by a large stone gargoyle that demands a password. When the correct password is provided, the gargoyle moves aside, revealing a spiral staircase that moves upward like an escalator, carrying visitors to the office door.
• Main Office: The primary circular room which houses the Headmaster's desk, the portraits of past Headmasters, and significant magical artifacts. This is where all meetings, lessons, and major revelations take place.

• In the film adaptations, the entrance to the office is a large, ornate griffin statue that unfurls its wings to reveal the staircase, rather than a stone gargoyle. The office itself is depicted as a vast, multi-level chamber combining a library and an observatory, far grander in scale than the single room described in the novels. (film)
• J.K. Rowling has stated that Dumbledore's passwords being sweets is a reflection of his slightly eccentric and good-natured character.
• The Pottermore website confirms that the office is one of the most secure locations in the castle and is enchanted to recognize the rightful Headmaster, sealing its secrets from usurpers like Dolores Umbridge. (Pottermore)