Rent Relief Act of 2017 This bill amends the Internal Revenue Code to allow a refundable tax credit for individuals who pay rent for a principal residence that exceeds 30% of the individual's gross income for the taxable year. The amount of the credit ranges from 10% to 100% of the excess, depending on the gross income of the taxpayer. The credit is not available for taxpayers with gross income that exceeds $125,000. Rent that exceeds 150% of the fair market rent for the residence may not be taken into account for the purpose of determining the amount of the credit. For individuals who reside in government-subsidized housing, the bill allows a credit equal to 1/12 of the rent paid by the taxpayer (and not subsidized under the program) during the year with respect to the residence.