This paper explores the significant impact of cybersecurity breaches on large businesses, focusing on financial losses, operational disruptions, reputational damage, and legal challenges. It examines key breach types such as data theft, ransomware, and phishing, and highlights the increasing complexity of cyber threats due to emerging technologies like AI, IoT, and 5G. Case studies, including Target and Equifax, demonstrate the long-term consequences of breaches. The paper emphasises the importance of proactive cybersecurity strategies, leadership involvement, and continuous adaptation to evolving threats. In conclusion, it underscores the need for businesses to invest in robust cybersecurity measures to protect assets, maintain consumer trust, and ensure long-term resilience in an increasingly digital world.