West Science Interdisciplinary Studies Vol. 02, No. 04, April and 2024: pp. 831-840 Journal homepage: https://wsj.westscience-press.com/index.php/wsis The Influence of Personal Branding, Influencer Endorsement, and Customer Engagement on Brand Affinity in the Cosmetics Industry in Indonesia Frans Sudirjo 1 , Darmiono 2 , Muhamad Ammar Muhtadi 3 1 Jurusan Manajemen, Fakultas Ekonomika dan Bisnis, Universitas 17 Agustus 1945 Semarang and frans- sudirjo@untagsmg.ac.id 2 Akademi Ketatalaksanaan Pelayaran Niaga Bahtera and darmiono1@gmail.com 3 Nusa Putra University and muhamad.ammar_mn19@nusaputra.ac.id ABSTRACT This quantitative study explores the influence of personal branding, influencer endorsement, and customer engagement on brand affinity within the cosmetics industry in Indonesia. A sample of 176 cosmetic consumers was surveyed, and data were analyzed using structural equation modeling (SEM) with partial least squares (PLS) path analysis. The findings reveal significant positive relationships between personal branding, influencer endorsement, customer engagement, and brand affinity. Specifically, personal branding and influencer endorsement were found to have strong positive effects on brand affinity, highlighting the importance of cultivating a distinct brand identity and leveraging influencer partnerships to resonate with consumers. Additionally, customer engagement emerged as a critical determinant of brand affinity, underscoring the value of fostering meaningful interactions and experiences with consumers. These findings provide valuable insights for cosmetic brands seeking to enhance consumer perceptions and behaviors, drive brand loyalty, and achieve long-term success in the Indonesian market. Keywords: Personal Branding, Influencer Endorsement, Customer Engagement, Brand Affinity, Cosmetics Industry 1. INTRODUCTION The cosmetics industry in Indonesia has experienced significant growth, with brands utilising various strategies to attract consumer loyalty [1]–[3]. From utilising K-Pop ambassadors to emotional marketing campaigns, brands such as Wardah and Make Over strive to increase brand affinity and awareness [4], [5] . In addition, the existence of illegal cosmetics underscores the importance of consumer protection and legal regulations in the market. Factors that influence Indonesian consumers' purchasing behaviour for Korean beauty products include consumer attitude, positive product image, and quality, highlighting the importance of these aspects in fostering brand loyalty. In this competitive landscape, understanding consumer perceptions, brand image, and experience is crucial for brands to build and maintain a strong emotional connection with Indonesian consumers, ultimately driving brand affinity and loyalty. Brand affinity is a complex concept influenced by various factors, such as consumer affinity, brand personality, and product trust. Consumer affinity, which denotes consumers' positive dispositions towards a foreign country or brand, plays a crucial role in shaping purchase intentions [6]–[8]. Additionally, personal branding, a strategic process of developing a brand identity that resonates personally with consumers, is vital in the cosmetics industry for fostering trust and loyalty [9]. The interplay between consumer affinity, personal branding, and other elements like influencer endorsement and customer engagement underscores the significance of creating authentic connections with consumers in industries where individuality and self-expression are paramount. In the cosmetics industry, influencer endorsement plays a pivotal role in shaping consumer perceptions and preferences. Social media influencers hold significant sway over purchasing