A process and catalysts for the direct oxidation of an olefin having three or more carbon atoms, such as propylene, by oxygen to an olefin oxide, such as propylene oxide. The process involves contacting the olefin under reaction conditions with oxygen in the presence of hydrogen and a catalyst. The catalyst contains silver and titanium, optionally gold, and optionally, at least one promoter element selected from Group 1, Group 2, zinc, cadmium, the lanthanide rare earths, and the actinide elements. Suitable supports include titanium dioxide, titanium dioxide on silica, titanosilicates, promoter metal titanates, titanium dispersed on silica and promoter metal silicates.