Localized surface plasmon resonances (LSPRs) are collective oscillations of conduction band electrons excited in plasmonic nanoparticles by electromagnetic (EM) radiation at resonant wavelengths. LSPR generates locally enhanced EM fields with optical photon absorption and scattering cross sections much larger than the physical nanoparticle size. Plasmonic nanoparticles have shown great promise in cancer therapy, solar photovoltaics, and photocatalysis due to localized heating and excited charge carriers produced through non-radiative LSPR damping. Energetically "hot" carriers generated from the plasmonic decay, termed hot electrons and hot holes, are known to promote redox reactions during fuel synthesis and decomposition of environmental pollutants. Furthermore, hot electrons can reduce nearby metal ions to deposit secondary metal layers onto plasmonic nanoparticle substrates, generating photocatalysts more efficient than either constituent metal alone. Rational photocatalyst design requires understanding how nanoparticle shape, composition, and surrounding environment impact plasmonic hot carrier generation. A range of experimental methods to obtain high-resolution information are applied to address the foregoing challenge. Dark-field scattering can monitor changes to the optical properties of an individual plasmonic nanoparticle; however, this diffraction limited technique cannot reveal sub-particle level details such as LSPR hotspots. Photoelectron detection methods have been employed to visualize hot electron generation from SiO2-Au core-shell nanoparticles and to spectroscopically characterize energy and lifetime distributions of hot electrons from gold nanorods, but they neglect hot electrons existing at sub-vacuum energy levels which may also be photocatalytically relevant. Modified atomic force microscopy (AFM)-based techniques such as photocurrent mapping and Kelvin probe force microscopy can provide snapshots of spatiallyvarying surface electrical properties arising from hot carrier transport across surfaces of particles or films. Using photoconductive AFM, Lee et al. visualized hot hole flux in Au nanotriangles under LSPR excitation and observed enhanced flux at the particle boundary relative to the interior, in agreement with field distribution simulations. Other spectroscopic and/or microscopy techniques based on surface-enhanced Raman spectroscopy (SERS), fluorescence or chemiluminescence can probe photochemical processes from a molecular perspective. Multiple techniques mentioned here permit incorporation of electrochemical measurements and/or ultrafast lasers to enable in situ monitoring of hot carrier-driven photochemical processes. Although experimental measurements have advanced insight into plasmonic hot carrier dynamics, fundamental mechanistic details about the spatial distribution of hot carrier injection sites and rates over the surface of individual plasmonic nanoparticles remain elusive. So far, the spatial distribution of hot carrier dynamics is primarily investigated with numerical simulations, which make assumptions about LSPR decay pathways and hot carrier energies.