GIS Day is a grassroots event that formalizes the practice of geographic information systems (GIS) users and vendors of opening their doors to schools, businesses, and the general public to showcase real-world applications of this important technology.

The National Geographic Society has sponsored Geography Awareness Week to promote geographic literacy in schools, communities, and organizations, with a focus on the education of children. There will also be many worldwide activities supporting geography action, with their goal being to engage people in learning and caring about geography.

The first GIS Day in Thailand occurred in 1999 from cooperation among many organizations and be sponsored by ESRI (Thailand) Co., Ltd. The main objectives of GIS Day are:
1. To introduce the importance of geography and environment that directly influence on people.
2. To give an understanding to people to know how can prevent our environment by using GIS technology.
3. To support Thai youths to use GIS tool for growth of our country and world.