Excessive preoccupation with the internet is common especially among undergraduate students. This study investigated the influence of personality traits and depression on internet addiction among undergraduate students of Benue State University, Makurdi, Nigeria. The study employed the cross-sectional survey design. Three instruments were pilot tested and items that met the criterion for retuning items on the scale based on their total correlation of not less than 0.30 were selected for the main study. The instruments used were, the Big Five Personality Inventory, Beck Depression Inventory and Young Internet Addiction Scale. Three Hundred and Ninety-one male and female students aged between 18-34 years (SD = 19.39) were randomly sampled and administered copies of the questionnaire. Three (3) hypotheses were postulated and data were analysed using Multiple Regression Analysis. Findings showed all the dimensions of personality traits significantly influenced internet addiction. There was also a significant influence of depression on internet addiction. Result findings indicated a significant joint influence of personality traits and depression on internet addiction among undergraduate students of Benue State University, Makurdi. Therefore, all three hypotheses were accepted. With regards to the findings, it was suggested among other things that healthcare practitioners including psychologists take special care and interest in proffering short and long term solutions to mitigating internet addiction.