Global Classrooms is a U.S.-based global education program created in 1999, belonging to the United Nations Association of the United States of America (UNA-USA), that engages middle school and high school students in an exploration of current world issues through Model United Nations, wherein students step into shoes of UN Ambassadors and debate a range of issues on the UN agenda. Global Classrooms was created primarily for students in economically disadvantaged public schools who have little or no knowledge of global affairs or experience with Model UN. The Global Classrooms program is currently in 24 major cities around the world.

Established in 2003, Global Classrooms®: Houston is the flagship program of UNA Houston. Through a global education curriculum that emphasizes the connectivity and interdependence of all nations, the program is designed for students in grades 6 – 12 from socio-economically disadvantaged public schools within Greater Houston. Lessons focus on the political, economic, social, and cultural issues facing the world today as well as the work of the United Nations and its affiliate organizations in bringing about peaceful solutions to these challenges. By using mini simulations of actual UN committee proceedings, the program strengthens student skills in research, writing, negotiation, and public speaking. The culmination of the program is a day-long conference in the spring of each year, usually held at a local university to promote continuation to higher educational pursuits. College students serve as the Secretariat, and diplomatic officials are invited keynote speakers.

Over the past 17 years, Global Classrooms Houston has reached over 10,000 students in the Houston area.