As a natural response to the ongoing trend of device miniaturization, many effects of scaling on the properties of materials have become well documented. However, the mechanical properties of individual nanoparticles are not well understood and the direct observation of nanoparticle deformation has only recently been achieved. This work investigates the mechanical behavior of silicon nanospheres in the transmission electron microscope (TEM) using an in situ indentation sample holder. In situ TEM studies provide information which is not accessible by more traditional means, including particle orientation prior to deformation and the type and location of any preexisting defects. In this study, isolated nanoparticles were located and compressed between a diamond tip and a sapphire substrate. Here, the deformation behavior of individual particles is investigated and analogous strain fields between small particles are discussed.