Restoring Communities Left Behind Act This bill directs the Department of Housing and Urban Development to establish a competitive grant program for local partnerships to carry out neighborhood revitalization support activities in economically distressed areas. Eligible activities include weatherization and energy efficiency improvements; housing accessibility improvements for seniors and persons with disabilities; purchasing delinquent mortgages; pre-purchase counseling and down payment assistance for prospective homebuyers; purchasing and developing vacant or distressed properties to create affordable rental housing and for other purposes; and improving parks, sidewalks, and street lighting.