This research investigates the enhancement of English public speaking skills among Thai EFL (English as a Foreign Language) students through imitating TED Talks videos. By applying Vygotsky's Zone of Proximal Development (ZPD) and Krashen's Input Hypothesis, the study integrates authentic materials for effective learning. A mixed methods approach, incorporating quantitative surveys, qualitative interviews and observation was used to assess students' perceptions and improvements in speaking skills. Fifty-five students from a government university in Northeastern Thailand participated in activities involving watching, imitating, and recording their own videos posted in a Facebook group. Results show significant improvements in vocabulary, grammar, body language, and overall speech structure. Students reported increased confidence and more engaging presentations. Initial challenges included understanding diverse accents and reliance on scripts, which decreased with practice. The study underscores the benefits of selective imitation over full imitation, allowing students to maintain individuality while acquiring new skills. These findings suggest that TED Talks are a valuable resource in English language teaching, fostering both linguistic and communicative development, and highlighting the importance of authentic materials and guided practice in language acquisition.