1. Introduction: Stellar Populations in the UV

2. UVOT Observing and Data Reduction

2.1. The Swift Ultraviolet Optical Telescope (UVOT)

2.2. Photometric Reduction of UVOT Images

2.3. Wide Field Stellar Photometry with UVOT

2.4. Comparison with Ground-Based Optical Photometry

3. UVOT UV and Optical Photometry of Four Star Clusters

4. Conclusions