This study aims to propose comprehensive improvements to tax policy in response to the significant social changes brought on by serious demographic shifts resulting from low birth rates and an aging population. Population structure changes can trigger economic downturns, erode national competitiveness, and even pose existential risks to the nation, making it imperative for the government to implement proactive strategies. A key tool in these national response measures is tax policy. Specifically, this study seeks to offer integrated solutions for six major tax categories-corporate tax, income tax, value-added tax (VAT), property tax, local taxes, inheritance tax, and gift tax-to address demographic changes effectively. To date, South Korea has employed various piecemeal tax measures to counter low birth rates and aging trends, but the effectiveness of these approaches has been limited. This research underscores the insufficiency of minor tax credits and emphasizes the necessity of a long-term, comprehensive tax strategy to effectively address demographic transitions. The findings of this study are as follows. First, corporate tax should be restructured to enhance competitiveness, with a focus on simplifying tax brackets and tax bases, implementing a reasonable tax rate, and aligning tax structures with new industrial transformations. Second, income tax reforms should include adjustments to tax systems and bases, a shift to a household-based tax unit, and the introduction of inflation-indexed tax schemes. Third, VAT reform requires a tax rate increase, improvements in exemption rules, and revisions to the simplified tax scheme. Fourth, property tax should be adjusted by switching to a household-based tax unit and introducing measures to reduce the tax burden on elderly taxpayers. Fifth, local tax policy should be refined to promote competitiveness through the integration of local governments into larger administrative units. Sixth, inheritance and gift taxes should be restructured to promote economic circulation, with a focus on abolishing taxes on spousal inheritance and gifts and indexing deductions to inflation. Lastly, to avoid distortions in elderly taxpayers’ economic and fiscal decision-making, tax policies must be carefully adjusted. This study recommends establishing a “Committee on Population Structural Change”, involving tax experts to devise and coordinate tax policies that directly support 1) economic growth and positive economic cycles, 2) policies to support higher birth rates, 3) support measures for the elderly, and 4) policies that encourage broader workforce participation, including that of women and foreign workers.