Self-directed learning ability had a significant positive direct effect on online student engagement (β = 0.511, t = 17.586, p < 0.001). Information literacy mediated the relationship between self-directed learning ability and online student engagement, with an indirect effect of 0.346, accounting for 67.7% of the total effect. Self-control negatively moderated the direct effect of self-directed learning ability on online student engagement (β = −0.310, t = −2.140, p < 0.01).