State and Local Cybersecurity Improvement Act This bill establishes a grant program and places requirements on the Cybersecurity and Infrastructure Security Agency (CISA) with respect to certain cybersecurity risks and threats. Specifically, CISA shall distribute grants to states for addressing cybersecurity risks and threats to the information systems of state, local, tribal, or territorial governments. A state applying for such a grant must (1) submit a cybersecurity plan for approval, and (2) establish a cybersecurity planning committee to assist with developing and implementing the state's cybersecurity plan and determining the effective funding priorities for the grant. CISA must establish a State and Local Cybersecurity Resiliency Committee whereby state, local, tribal, and territorial governments can advise CISA on their cybersecurity needs. In addition, CISA must develop and make publicly available a Homeland Security Strategy to Improve the Cybersecurity of State, Local, Tribal, and Territorial Governments that provides recommendations regarding how the federal government should support and promote the ability of such governments to protect against, respond to, and recover from cybersecurity risks, threats, and incidents. Further, CISA must develop a resource guide to assist officials of such governments with cybersecurity risks, threats, and incidents. CISA must also conduct a study to assess the feasibility of implementing a short-term rotational program for the detail of approved state, local, tribal, and territorial government employees in cyber workforce positions to the agency.