Santissimo Sacramento e Caterina da Siena was an oratory on a site now occupied by Via della Lupa 10-11, in the rione Campo Marzio.
The Nolli map of 1748 shows a little oratory on a rectangular plan, divided almost equally into nave and presbyterium by a triumphal arch. It was demolished and replaced with a domestic building later in the century.
The map index indicates that it was occupied by a lay confraternity of the same name, attached to the nearby church of San Nicola dei Prefetti. Back then this church was being administered by the Dominicans of Santa Sabina, and this explains the dedication to a Dominican saint.