This experimental study investigated the effects of flipped classroom in enhancing critical thinking and reading comprehension levels of 212 senior high school ESL learners in the Philippines; half of which received the conventional lecture-discussion approach to instruction and the other half received flipped learning approach.  Both the control and the experimental groups were subjected to equal number of 15 instructional sessions.  In order to establish the baseline data for each group in the critical thinking variable and the reading comprehension variable, pretests were conducted and were subsequently compared to posttest results.  The t-test of two independent samples assuming equal variances was used to determine if there was a significant difference between the flipped classroom approach and the lecture-discussion approach with regard to enhancing critical thinking and reading comprehension levels.  Results reveal that in both approaches, there were improvements in the critical thinking levels and the reading comprehension levels of the respondents.  However, the results reveal that the respondents who received instruction using the flipped learning approach significantly outperform the respondents who received conventional instruction.