Mathematical modeling is becoming established in the immunologist's toolbox as a method to gain insight into the dynamics of the immune response and its components. No more so than in the case of the study of human immunodeficiency virus (HIV) infection, where earlier work on the viral dynamics brought significant advances in our understanding of HIV replication and evolution. Here, I review different areas of the study of the dynamics of CD4⁺ T cells in the setting of HIV, where modeling played important and diverse roles in helping us understand CD4⁺ T‐cell homeostasis and the effect of HIV infection. As the experimental techniques become more accurate and quantitative, modeling should play a more important part in both experimental design and data analysis.