Housing for Afghan Allies Act of 2021 This bill allows state and local governments receiving emergency rental assistance funds for unemployed persons, persons with hardship related to the COVID-19 pandemic, and persons at risk of homelessness to use some of those funds to provide rent and utility assistance to certain individuals and families from Afghanistan. The funds may be used to provide such assistance to individuals and families who are citizens or nationals of Afghanistan, who are present within the United States, and who have been granted special immigrant status or have received priority 2 refugee designation. A special immigrant is an immigrant who qualifies for a permanent residence after meeting certain criteria. A priority 2 refugee designation grants U.S. Refugee Admissions Program access to certain immigrants, including Afghan immigrants who do not qualify as special immigrants but who may be at risk because of their U.S. affiliation.