We report on observations of the blazar W Com (ON+231) with the Solar Tower Atmospheric Cerenkov Effect Experiment (STACEE), a wave front-sampling atmospheric Cerenkov telescope, in the spring of 2003. In a data set comprising 10.5 hr of on-source observing time, we detect no significant emission from W Com. We discuss the implications of our results in the context of the composition of the relativistic jet in W Com, examining both leptonic and hadronic models for the jet. We derive 95% confidence level upper limits on the flux at the level of (1.5-3.5) × 10-10 cm-2 s-1 above 100 GeV for the leptonic models, or (0.5-1.1) × 10-10 cm-2 s-1 above 150 GeV for the hadronic models.