Small Airport Regulation Relief Act of 2023 This bill allows commercial service airports that do not meet the minimum passenger boarding requirement to continue to receive certain Airport Improvement Program (AIP) funding from the Federal Aviation Administration (FAA) for a limited time. The AIP provides grants for planning and development projects at public-use airports, including primary airports. Under current law, primary airports are generally commercial service airports that have more than 10,000 passenger boardings each year. Specifically, this bill creates a special rule for FY2024-FY2026 for commercial service airports that (1) had fewer than 10,000 passenger boardings during the calendar year used to calculate the apportionment, and (2) had 10,000 or more passenger boarding in calendar year 2019. For the purpose of AIP grant apportionment, the bill requires the FAA to use the number of passenger boardings at the airport during calendar year 2019, 2020, or 2021 (whichever had the highest number of passenger boardings).