Due to its semiconductive properties, silicon has been widely used and still represents the basis of electronics-related technologies. Despite having properties often very different from the pure element, silicon derivatives (e.g., SiO2, SiC, and silanes) are widely exploited as well in a variety of fields, ranging from photonic to biomedicine. Besides the traditional applications, the wide spreading of nanostructures, with their enhanced and in some respect unexpected properties, is now opening new perspectives for the possible uses of silicon and its derivatives. In this thematic special issue, our purpose was to highlight cutting-edge technologies and most modern applications related to these materials, especially at the nanoscale. We are glad to announce that the five original research papers published here, which we will briefly present in the following, all perfectly fit with our starting aim.