The American Society for Engineering Education notes the following free, online STEM contests open to students:

• MathWorks Math Modeling Contest:  Grades 11 & 12 — up to 2 teams per school, of 2-3 students each — tackle real-world math problems online under time and resource constraints. Register by February 19 at 4PM.
• New York Times STEM Writing Contest: Middle/High school students ages 11-19 write an engaging, 500-word explanation of a STEM-related issue or question of their choice. January 19 – March 2.
• ACTE/NASA Student Video Contest: Students of all ages create videos on the theme of Advancing Space Exploration through Manufacturing. Submit entries by April 1.
• EngineerGirl Writing Contest: Grades 3-5, 6-8, and 9-12 submit essays by February 1(!) about engineering’s role in meeting and defeating the challenges presented by COVID-19.