Background: Peer pressure to drink alcohol may influence excessive alcohol consumption, which can have adverse impacts on health and wellbeing. While peer pressure to drink alcohol is extensively studied among youth, less examination exists among adults. This systematic review examined qualitative research studies which explored the role and concept of peer pressure within the context of alcohol consumption in adults living in the UK. Methods: Qualitative studies which explored peer pressure within the context of alcohol consumption or alcohol related behaviours and views in adults (age range approximately 18-52 years) living in the UK were included. Systematic searches conducted in Medline, PsycINFO and Web of Science identified 1462 references, of which 13 studies met inclusion criteria. Thematic analysis was conducted. Results: Five overarching themes were identified. Four of these themes directly address aspects of peer pressure, including: experiences of peer pressure; consequences of peer pressure; strategies to deal with peer pressure; and conditions perceived to affect peer pressure. The fifth overarching theme explains the wider social context influencing peer pressure. Pressure to drink alcohol affects individuals across the life span and can be experienced as overt and aggressive, or subtle and friendly. Those consuming little or no alcohol are more likely to feel overt forms of peer pressure. Some developed strategies to cope with pressure from drinkers. Peer pressure can result in feelings of social isolation, or giving in by consuming alcohol against ones wishes. Conclusion: Peer pressure to drink alcohol is a complex and multifaceted phenomenon experienced across adulthood requiring better understanding to support initiatives to decrease the impact of pressure-inducing environments and develop strategies to deal with perceived pressure conditions.