This paper presents a systematic literature review of influencer marketing-based consumer behaviour, covering 60 peer-reviewed studies published between 2019 and 2025. The review identifies key influencing factors such as credibility, Para social interaction, content quality, and social identity, and categorizes them using a modified Input–Process–Output (IPO) model. Four major dimensions are examined: influencer characteristics, consumer psychology, behavioural outcomes, and platform-specific elements. Commonly applied theories include the Source Credibility Theory, Social Identity Theory, and the Heuristic-Systematic Model. The study highlights research gaps, including limited longitudinal analysis, cultural diversity, and the ethical challenges of emerging technologies like AI influencers. A future research agenda is proposed to guide scholars towards unexplored areas such as sustainable influence and micro-influencer impact. The findings offer a comprehensive foundation for understanding how influencer marketing shapes consumer attitudes and decision-making in the evolving digital landscape
Eugene Cheng‐Xi AwRaj Agnihotri
Jerum William KilumileJohakim Katekele John
Pearl Fafa BansahVanessa GaffarDisman DismanAyu Krishna Yuliawati
Divyaneet KaurShiksha KushwahSatish Kumar
Seyyed Mohammadhossein AlipourMohammad GhaffariHamid R. Zare