The consequences of alcohol and other drug (AoD) use are well documented. This study investigated factors associated with having family/whānau or close friend who used AoD in harmful ways in New Zealand. Data came from a July–August 2020 cross-sectional survey of students from eight universities (n = 946). Participants were asked if they had family/whānau or close friends in New Zealand who consumed alcohol or used other drugs (cannabis, ecstasy/MDMA, methamphetamine, cocaine, heroin, prescription drugs, inhalants, or other) in a way that negatively impacted them, their family, or close friends in the last 12 months. Logistic regression assessed associations of having family/whānau or close friend who used AoD harmfully with student characteristics. Of respondents, 36.2% (33.1–39.4) had family/whānau or close friend who had consumed alcohol harmfully, and 42.9% (39.5–46.3) had family/whānau or close friend who had used at least one drug harmfully. Respondents’ age and ethnicity were significantly associated with having family/whānau or close friend who used AoD harmfully. The results suggest widespread harmful AoD use and potentially significant second-hand effects of AoD use in New Zealand. These data can be used to supplement information from traditional in-person surveys of individuals using alcohol and other drug (e.g., the New Zealand Health Survey).