The lack of defined land uses in most parts of Greece (80%) has led to multiple environmental problems and phenomena of informal (arbitrary) construction with secondary side effects, such as a lack of basic technical and environmental infrastructure, unfair competition among private investors, the strengthening of climate change (increase in the number of urban diffusion) and the decline of natural and cultural resources. The Greek urban policy, over the last 100 years, has not succeeded in limiting these problems and for that reason the new Law 4759/2020 is expected to promote the development of a more efficient spatial planning system reform implemented through the Local Urban Plans (LUPs) and the Special Urban Plans (SUPs) that are funded by the Recovery and Resilience Facility (RRF). These programs will contribute to the preservation of cultural heritage and to the development of productive activities at both local and national levels, especially on the sectors of renewable energy sources, the circular economy, and the construction of “green” materials, digital applications and products etc. LUPs and SUPs are related to the holistic reform of the national urban policy and the relevant planning system that horizontally affects a wide range of policy areas such as: environmental protection and adaptation to climate change (for natural ecosystems and biodiversity; agriculture; forestry; fisheries; water resources; coastal zones), built environment and development, protection of historic sites and buildings, allocation of the public infrastructure, allocation of investments etc. The General Secretariat of Spatial Planning and Urban Environment Ministry of Environment and Energy has the main responsibility for the implementation procedures of all the proposed actions that will start in 2022 and will end in 2026. This paper focuses on the analysis of the current urban policy reform in Greece and the reasons that this reform is considered an immediate necessity in the current Greek urban legislative framework and the expected outcomes of LUPs and SUPs, which are examined in the literature for the first time, contributing to research on the present EU planning systems.