Youth in juvenile justice (JJ) facilities lack access and exposure to high-quality science, technology, engineering, and math (STEM) instruction, career exploration, and employment opportunities. Research on STEM knowledge and career interest of JJ involved youth is virtually non-nonexistent. The purpose of this study was to ascertain how JJ students think about STEM, how they perform on STEM tasks, and what STEM jobs or careers they are interested in prior to designing a STEM curriculum specific to this population. Findings related to STEM knowledge, STEM interest, and STEM job interest are reported and implications are discussed.