Dragon Day is an annual event that occurs the Friday before spring break at Cornell University. The center of the event is the procession of a dragon, created by first-year architecture students at the Cornell University College of Architecture, Art, and Planning. The construction is funded by selling Dragon Day t-shirts.

The first event was in 1901. Believing that there should be a "College of Architecture Day," student Willard Straight of the class of 1901 led a group of architecture students around campus carrying a model dragon. This was partly inspired by the legend of St. Patrick driving all the snakes and serpents from Ireland. Lincoln Hall, which housed the College of Architecture at the time, was decorated with orange and green banners, shamrocks, and themed decorations. In the 1950s, the event evolved into its current form, with an actual constructed dragon. It is unknown when the term "Dragon Day" was coined, but it likely came into use in the 1950s. Since then, the holiday has turned into a parade for the dragon.

Typically, the dragon is built by the entire first year architecture class as a bonding and team-building exercise. Although the parade takes place over a few hours, the event requires at least six weeks of planning and preparation beforehand. The event is fully student-funded, primarily through selling commemorative t-shirts.

Although it is typically carried from beneath by architecture students, in 1964 and 1976 the dragon was mounted on a car and driven through the route. In 1985, the dragon fell over as it rounded Sibley Hall, and was not able to complete its route. In 2009, due to new New York State Department of Environmental Conservation regulations, the dragon was not burned at the end of the parade route; the dragon's "nest" was burned instead. Since the dragon can no longer be burned, various tactics have been employed to create a climactic spectacle. In 2012, first year architects squirted the dragon with paint. And in 2013, the white dragon was colored with multicolored Holi powder throughout the parade and at the Arts Quad finale.

Dragon Day festivities were cancelled in 2020 and 2021 due to the COVID-19 pandemic. The 2022 dragon was larger than usual. It was constructed by two AAP classes, and sported two heads to represent the two classes.

2023 marked a very strong comeback to Dragon Day since the pandemic. The freshman class sported a colorful dragon covered in recycled fabric with a rather cartoonish face. It was paraded through campus and destroyed at the ending ceremony in the Arts Quad. Its wings were placed on an installation in the Arts Quad.

Dragon Day has been used as a form of political expression. At some point between its origin and 1920, the festivities were banned by Cornell's third president, Jacob Gould Schurman, because campus Catholics were offended by the theme. During the 1933-1934 school year, students constructed a large paper-mache beer stein to celebrate the repeal of Prohibition. In the 1950s, Dragon Day was cancelled in protest of Senator McCarthy's red scare. In 1968, the dragon was controversially painted entirely black in protest of the Vietnam War. In 1994, the possible cancellation of the Cornell in Rome architecture program prompted students to adopt a "Fall of Rome" theme.

Campus pranks often surround Dragon Day. In 1966, a green pig was released into the Ivy Room, a dining hall, resulting in a massive food fight. In 1974, artist Oded Halahmy threatened to remove his outdoor sculptures from the campus after some were splattered with green paint and moved. The week before Dragon Day, the freshmen architects can be found running through campus lecture halls, barely clothed and painted green. At night, they moon the windows of Uris Library's Cocktail Lounge. In 1990, the Department of Architecture severed all ties with the holiday due to the pranks, but began re-affiliating with it in 1993.