The online death indexes directory now has a new separate webpage for St. Louis, Missouri...
Online St. Louis Death Records Indexes, Obituaries and Cemeteries
There you will find links to online St. Louis and Missouri death indexes, obituary indexes for the St. Louis Post-Dispatch, some cemetery burial indexes, a St. Louis Coroner's index, ordering information for Missouri death certificates, and more.
For other Missouri cities and counties see: Online Missouri Death Records Indexes, Obituaries and Cemeteries