This comprehensive study investigates the multifaceted impact of TikTok usage on English language acquisition among adolescent students in HKBP Siantar Timur. Employing a mixed-methods approach, this research delves deep into how TikTok influences various aspects of language learning, including vocabulary acquisition, listening comprehension, speaking skills, and cultural awareness. The study surveyed 21 teenagers aged 15-17, meticulously analyzing their TikTok usage patterns, language preferences, learning strategies, and perceived impacts on English proficiency. Additionally, in-depth interviews were conducted with a subset of participants to gain richer insights into their experiences and perceptions. Results indicate that while TikTok offers engaging and diverse content for language learning, students face significant challenges such as distraction, content reliability, and the need for critical digital literacy skills. The study reveals complex relationships between TikTok usage frequency, content types, and perceived language improvements. Notably, students who actively engaged with educational content and international users reported higher perceived gains in language skills. This research provides nuanced insights for educators, policymakers, and researchers on leveraging social media platforms for language education in the digital age. It highlights the need for structured guidance, curated content, and the development of digital literacy skills to maximize the potential of platforms like TikTok in formal and informal language learning contexts.