Globally, English is a popular second language that is not only used for official communication, but also used as the language of instruction in many learning institutions. Being proficient in English Language enables learners to interpret and derive meaning from written texts, thereby enhancing comprehension, supporting critical thinking, problem solving, and effective communication skills, all, which are essential for understanding other subjects. Consequently, English is regarded as a fundamental component of the educational curriculum. Despite the importance of English language, reading comprehension still remains a challenge for many learners. There are limited studies on the relationship between social support and English language reading comprehension self-efficacy. This study therefore, examined social support as a correlate of English language reading comprehension self-efficacy among Grade Six learners in Gatundu South Sub-County, Kenya. Self-Determination Theory and Self-Efficacy Theory guided the study. Correlational research design was used. The target population comprised of 3,220 Grade Six learners in 2025. Simple random sampling was employed to select respondents whereas stratified and proportionate sampling methods were employed to select schools. A sample of 356 learners participated in the study. A social support questionnaire and a Questionnaire of English self-efficacy (QESE) were used to collect the data. Data analysis was done using both descriptive and inferential statistics. The results showed that there is a moderate, positive, and statistically significant correlation between social support and reading comprehension self-efficacy (r = 0.39, p < 0.001). This indicates that increased support from teachers, peers, and parents is associated with higher levels of learners’ confidence in reading comprehension. The study recommends implementing structured school-based reading support programmes, strengthening teacher and parental involvement in learners’ reading activities, promoting peer-assisted learning, providing regular formative feedback, and increasing access to age-appropriate reading materials to enhance learners’ reading comprehension self-efficacy.