Critical infrastructure systems, including power grids, water supply, transportation, telecommunications, and healthcare, are increasingly dependent on digital technologies and interconnected networks. This digital transformation, while enhancing efficiency and innovation, also exposes these essential services to growing cyber threats. Cybersecurity in infrastructure is vital to protect operational technology (OT) and industrial control systems (ICS) that manage physical processes in real time. These systems face unique challenges such as legacy hardware, complex networks, and the necessity for uninterrupted operation. Common cyber threats targeting critical infrastructure include malware, ransomware, phishing, advanced persistent threats (APTs), insider threats, and denial-of-service (DoS) attacks. The consequences of security breaches can be severe, leading to service disruption, economic loss, public safety risks, and compromised national security. Effective cybersecurity strategies involve comprehensive risk assessments, network segmentation, continuous monitoring, incident response planning, stringent access controls, employee training, and regular patch management. Emerging technologies such as artificial intelligence, machine learning, and blockchain are being leveraged to enhance threat detection, data integrity, and system resilience. As cyber threats evolve, safeguarding critical infrastructure requires collaboration among governments, private sectors, and stakeholders to implement robust defense mechanisms. This paper emphasizes the importance of a multi-layered cybersecurity approach to ensure the reliability and security of critical infrastructure vital to modern society and economic stability.