According to the standard definition, creative ideas must be both novel and useful. While a handful of recent studies suggest that novelty is more important than usefulness to evaluations of creativity, little is known about the contextual and interpersonal factors that affect how people weigh these two components when making an overall creativity judgment. We used individual participant regressions and mixed-effects modeling to examine how the contributions of novelty and usefulness to ratings of creativity vary according to the context of the idea (i.e., how relevant it is to the real world) and the personality of the rater. Participants (N = 121) rated the novelty, usefulness, and creativity of ideas from two contexts: responses to the alternative uses task (AUT) and genuine suggestions for urban planning projects. We also assessed three personality traits of participants: openness, intellect, and risk-taking. We found that novelty contributed more to evaluations of creativity among AUT ideas than projects, while usefulness contributed more among projects than AUT ideas. Further, participants with higher openness and higher intellect placed a greater emphasis on novelty when evaluating AUT ideas, but a greater emphasis on usefulness when evaluating projects. No significant effects were found for the risk-taking trait.