This is a recording of a meeting titled "Supermassive Black Hole Studies with the Legacy Survey of Space and Time: 2021" held remotely over Zoom on 2021 July 12-14. The meeting was organized by the Rubin Observatory Legacy Survey of Space and Time (LSST) Active Galactic Nuclei (AGN) Science Collaboration. The organizers were Roberto J. Assef (Universidad Diego Portales; Chile), W. Niel Brandt (Penn State University; USA), Luka C. Popovic (Astronomical Observatory, Belgrade; Serbia), and Gordon Richards (Drexel University; USA). There are three talks in this recorded part with talk titles and speakers as follows: "LSST DESC Recommendations for DDF Strategy" - Dan Scolnic (Duke Univ) "Forced photometry, photometric redshifts, and SEDs of sources in the LSST Deep Drilling Fields" - Fan Zou (Penn State Univ) "XMM-SERVS: A Sensitive X-ray Survey of the LSST Deep-Drilling Fields" - Qingling Ni (Penn State Univ) Please refer to the other parts for the other talks. Each talk is about 25-30 min long including time for questions/discussion. Some more details about the LSST AGN Science Collaboration and related topics can be found at https://agn.science.lsst.org/ The YouTube links for the 6 meeting parts are the following: Part 1: • Supermassive Black Hole Studies with the L... Part 2: • Supermassive Black Hole Studies with the L... Part 3: • Supermassive Black Hole Studies with the L... Part 4: • Supermassive Black Hole Studies with the L... Part 5: • Supermassive Black Hole Studies with the L... Part 6: • Supermassive Black Hole Studies with the L...