The word Gan or the abbreviation GAN may refer to:

• Gan Chinese, a variety of spoken Chinese spoken in Jiangxi, Fujian and Hunan.
• GaN, an abbreviation for Gallium nitride
• Gan, a common family name in South East Asia of typically Chinese descent from Fujian who speak the Min Nan or Hokkien dialect. 顏](Traditional Chinese), 颜](Simplified)
• GAN (cycling team), the former name of the Crédit Agricole cycling team
• Giant axonal neuropathy and is also the name of the gene that when mutated causes the disorder
• Grant Anticipation Note, a type of highway financing

Gán is a village and municipality in Galanta District of the Trnava Region of south-west Slovakia.

Gallium nitride (N) is a binary III/V direct bandgap semiconductor commonly used in bright light-emitting diodes since the 1990s. The compound is a very hard material that has a Wurtzite crystal structure. Its wide band gap of 3.4 eV affords it special properties for applications in optoelectronic, high-power and high-frequency devices. For example, GaN is the substrate which makes violet (405 nm) laser diodes possible, without use of nonlinear optical frequency-doubling.

GanttProject is GPL-licensed (free software) Java based, project management software that runs under the Windows, Linux and Mac OS X operating systems. This project was initiated in January 2003, at and managed, at first, by Alexandre Thomas, now replaced by Dmitry Barashev.

Jiangxi (; Gan: Kongsi) is a province in the People's Republic of China, located in the southeast of the country. Spanning from the banks of the Yangtze river in the north into hillier areas in the south and east, it shares a border with Anhui to the north, Zhejiang to the northeast, Fujian to the east, Guangdong to the south, Hunan to the west, and Hubei to the northwest.