Marion High School is a high school located in the growing city of Marion, Illinois, serving the Marion Unit 2 School District. The school's enrollment was approximately 1,125 students in the 2013–2014 school year. Marion Unit #2 School District built a new high school on the same property, that is completely finished.

In addition to Marion it serves Creal Springs and Pittsburg.

The current building has over 100,000 square feet (9,300 m) of space, with the previous building about 50% of the size. The proposed cost was $65 million. Construction on the facility began in 2012, with a wing for fine arts scheduled to be finished in 2017. It includes geothermal heating.

In 2017 Marion Unit #2 opened a new 330,000 square foot, state-of-the-art high school. It's design is unrivaled in Southern Illinois for both academics and extra-curricular activities. The new campus accommodates 21st-century learning with a science and technology (STEM) lab, a performing and visual arts center, a technical and vocational education center including learning labs in culinary arts, agricultural science, building trades, and automotive repair. The new facility includes a new health education center with an indoor track, multiple courts, a dance rehearsal area, and a fitness center. The educational wing better accommodates the wide variety of honors, advanced placement, capstone vocational courses, and college dual credit opportunities that prepare students for experiences in the workplace and at universities and colleges throughout the nation.

In 2015 the students began using Chromebooks. Marion Unit #2 is also making great strides in the area of technology by becoming a Google for Education School District. In August 2020, each K-12 student received a Chromebook to accommodate digital and extended learning experiences. Deploying one device per student to better engage and prepare students for learning opportunities.

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