Adolescents may be particularly vulnerable to the effects of caffeine due to a lack of tolerance, their small size, changing brain physiology, and increasing independence. Concerns about adolescent caffeine consumption relate to potentially serious physiological and psychological effects following consumption. Motivations driving caffeine intake are not well understood among adolescents but are important to understand to reduce harmful behavioural patterns. This study explored caffeine consumption habits (sources, amount, frequency) of New Zealand adolescents; and factors motivating caffeine consumption and avoidance. The previously validated caffeine consumption habits questionnaire (CaffCo) was completed by 216 participants (15–18 years), with most (94.9%) consuming at least one caffeinated product daily. Chocolate, coffee, tea, and kola drinks were the most consumed sources. The median caffeine intake was 68 mg·day−1. Gender (boy) and being employed influenced the source, but not the quantity of caffeine consumed. One-fifth (21.2%) of adolescents consumed more than the recommended European Food Safety Authority (EFSA) safe level (3 mg·kg−1·day−1). Taste, energy, and temperature were the main motivators for consumption, and increased energy, excitement, restlessness, and sleep disturbances were reported effects following caffeine consumption. This study provides information on caffeinated product consumption among New Zealand adolescents, some of whom consumed caffeine above the EFSA safe level. Public health initiatives directed at adolescents may be important to reduce potential caffeine-related harm.