This study explored how courtroom design and jurors' ideological attitudes influence guilt perceptions and sentencing. It hypothesized that defendants in secure docks would be perceived as more likely guilty and receive harsher sentences than those at the bar table, with stronger ideological attitudes increasing guilt likelihood. In a between‐subjects design, 556 participants reviewed courtroom sketches and case summaries, then rated guilt and sentencing. Defendants in secure docks were more often seen as guilty, and ideological attitudes partially influenced assessments. The findings highlight the need for interventions to reduce bias in legal proceedings and inform policy on courtroom design.