This study examined inequalities in college knowledge across the high school years. Twelfth graders had significantly more college knowledge than ninth and 10th graders. Although college knowledge increased during high school among both first- and continuing-generation college-going students, we found significant between-group differences. Continuing-generation students had significantly more college knowledge than first-generation students, and the gap between groups widened across the high school years. School counselors are uniquely positioned within the K-12 education system to address inequalities such as the college knowledge gap through their roles as educators and leaders.