This study explores Iranian EFL learners' online reading metacognitive strategy use and its relation to their self-efficacy in reading comprehension. It further examines the effect of gender in this respect. To these ends, the Online Survey of Reading Strategies (OSORS) and reading selfefficacy questionnaire were adopted and administered to 63 homogeneous sophomore EFL learners. To analyze data, Friedman Test and Multiple Analysis of Variance (MANOVA) were run. Results of Friedman test indicated that problem-solving online metacognitive reading strategies are most frequently used by the learners, while support strategies are used least frequently. The findings of MANOVA further revealed a significantly positive relationship between the learners' perceived use of metacognitive online reading strategies and their self-efficacy in reading comprehension. The study further revealed that females use more global online reading strategies, while males perceive themselves as more self-efficacious in reading online texts. Finally, the analysis of think aloud protocol indicated that learners used some other metacognitive strategies while reading online. The findings may have contributions to EFL learners' online reading strategy use and training and can highlight the significant role that self-efficacy might play in the use of metacognitive reading strategies while reading online.