Sustainable development requires the responsible management of natural resources while ensuring social and economic well-being for present and future generations. Although sustainable development is often associated with environmental science, technology and policy, mathematics plays a fundamental and often under-recognized role in achieving sustainability. Mathematics provides tools for measuring, analysing, predicting and optimizing the use of limited resources. Concepts such as statistics, percentages, ratios, probability, mathematical modelling, optimization, geometry, algebra and calculus can be applied to real-world sustainability challenges including climate change, water conservation, renewable energy, sustainable agriculture, waste management, transportation, population growth and resource allocation. The present paper explores how mathematical concepts can contribute to sustainable development and demonstrates their application through practical examples. It also discusses the role of mathematics education in developing sustainability-oriented thinking among learners. The paper argues that mathematics should be connected with real-life environmental and social problems so that learners understand mathematics not merely as a computational subject but as a powerful tool for informed decision-making and sustainable living. Integrating sustainability into mathematics education can develop quantitative literacy, critical thinking, problem-solving abilities and responsible citizenship.