Penelitian ini mengkaji dampak aktivitas pemasaran media sosial Instagram terhadap loyalitas merek Starbucks Coffee melalui ekuitas merek. Dengan menggunakan pendekatan kuantitatif, penelitian ini berfokus pada generasi milenial berusia 24–39 tahun yang merupakan pengguna aktif Instagram dan konsumen Starbucks di wilayah Jabodetabek. Model Stimulus Organism-Response (SOR) digunakan sebagai kerangka konseptual, dengan lima dimensi aktivitas pemasaran media sosial: entertainment, customization, trandiness, interaction, dan word of mouth. Tujuan penelitian ini adalah menganalisis pengaruh aktivitas pemasaran media sosial terhadap kesadaran merek (brand awareness), kepercayaan merek (brand trust), dan citra merek (brand image), serta bagaimana dimensi-dimensi ekuitas merek tersebut memengaruhi niat pembelian ulang (repurchase intention). Data dikumpulkan melalui kuesioner yang didistribusikan kepada 479 responden. Hasil analisis menggunakan Partial Least Squares-Structural Equation Modeling (PLS-SEM) menunjukkan bahwa semua dimensi aktivitas pemasaran media sosial memiliki pengaruh positif terhadap ekuitas merek. Selain itu, kesadaran merek, kepercayaan merek, dan citra merek secara signifikan meningkatkan loyalitas merek dan niat pembelian ulang konsumen. Hasil penelitian ini memberikan wawasan praktis bagi Starbucks dan bisnis serupa untuk mengembangkan strategi pemasaran digital yang lebih efektif melalui media sosial. Secara teoritis, penelitian ini memperkaya literatur terkait pemasaran digital, khususnya dalam konteks ekuitas merek dan loyalitas merek melalui aktivitas media sosial. / This study examines the impact of Instagram social media marketing activities on Starbucks Coffee brand loyalty through brand equity. Using a quantitative approach, this study focuses on millennials aged 24-39 who are active Instagram users and Starbucks consumers in the Jabodetabek area. TheStimulus-Organism-Response (SOR)model was used as the conceptual framework, with five dimensions of social media marketing activities: entertainment, customization, trandiness, interaction, and word of mouth. The purpose of this study is to analyze the effect of social media marketing activities onbrand awareness, brandtrust, and brandimage, and how these dimensions of brand equity affect repurchase intention. Data were collected through questionnaires distributed to 479 respondents. The results of the analysis using Partial Least Squares-Structural Equation Modeling (PLS-SEM) show that all dimensions of social media marketing activities have a positive influence on brand equity. In addition, brand awareness, brand trust, and brand image significantly increase brand loyalty and consumer repurchase intentions. The results of this study provide practical insights for Starbucks and similar businesses to develop more effective digital marketing strategies through social media. Theoretically, this study enriches the literature related to digital marketing, particularly in the context of brand equity and brand loyalty through social media activities.