Young adults on college campuses have easy access to information and communications technology (ICT) which they use extensively for study, work, and leisure. The purpose of this study was to investigate the prevalence and extent of problematic Internet use, online gaming behavior, and online gambling behavior (together referred to as dysfunctional online behaviors), and their relationships with depression and quality of life among college students. Two hundred and twenty two valid surveys were used in the data analyses. Five instruments, Beck Depression Inventory-II (BDI-II), the WHO Quality of Life Scale-BREF (WHOQOL-BREF), the Internet Addiction Test (IAT), the Problematic Online Gaming Questionnaire (POGQ), and the Online Gambling Symptom Assessment Scale (OGSAS), were selected to measure the variables being studied. A nonexperimental research design was employed to answer one descriptive and two research questions. The results of the analyses indicated that dysfunctional online behaviors predicted a higher level of depression (R[superscript 2] = 0.14, p < 0.05) and a lower level of quality of life (R[superscript 2] = 0.20, p < 0.05). The findings of the current study inform clinical practice and the treatment of dysfunctional online behaviors among college students.