Self-efficacy in English language is characterized as the ability to communicate in English through the mastery of reading, writing, speaking, and listening skills. It is a factor that appears to influence student achievement; however, it is likely that students do not have many opportunities to use English in their daily lives and have a limited understanding of the language. This study aimed to ascertain whether English Language Strategies and Social Media Use could significantly determine Self-efficacy in English language skills among Senior High School students in Davao City. Utilizing quantitative descriptive-correlational research, the study involved 250 senior high school students in Davao City, Philippines from five schools that offer Grade 11 and Grade 12 curriculum in school year 2021-2022. The results revealed that the overall senior high school students’ Language Learning Strategies, Social Media Use and Self-efficacy in English language skills were high which means that the variables under study were evident. Moreover, it was found that Language Learning Strategies and Social Media Use were significant determinants of Self-efficacy in English language skills.