This study investigated the longitudinal associations between children's Internet information seeking, life satisfaction, and feelings of loneliness as well as the mediating and moderating role of self-esteem in these associations. A total of 455 Chinese elementary school students participated in two waves of a survey with a 6-month interval, and 19 of these students participated in focus group interviews. The results indicated that seeking school- and life-related information on the Internet predicted more life satisfaction and less loneliness through improved self-esteem. Furthermore, self-esteem moderated the effects of Internet information seeking on loneliness. Internet information seeking predicted less loneliness only for children with low self-esteem. A moderating role of self-esteem in the associations between Internet information seeking and life satisfaction was not found in this study.