The rapid adoption of cloud computing technologies has transformed the way organizations design, develop, and manage complex projects. Cloud-based environments, characterized by their distributed architectures, dynamic scaling, and multi-tenancy features, offer enhanced flexibility and scalability. However, these benefits also introduce new layers of complexity and vulnerability, making risk assessment and mitigation more challenging than in traditional IT infrastructures. This explores the latest advances in risk assessment and mitigation strategies specifically tailored for complex cloud-based project environments. Modern risk landscapes in the cloud are shaped by evolving cybersecurity threats, compliance demands, integration challenges, and operational uncertainties. Traditional risk assessment models often fall short in capturing the dynamic and interconnected nature of cloud ecosystems. In response, recent developments have introduced advanced techniques such as AI-driven threat detection, real-time risk monitoring, and scenario-based probabilistic modeling. These innovations enable proactive identification and prioritization of risks, allowing for more agile and adaptive mitigation responses. Mitigation strategies have also evolved significantly, with the rise of cloud-native security controls, DevSecOps practices, and resilience engineering methods like chaos testing. Organizations are increasingly adopting Zero Trust architectures and automated incident response frameworks to enhance their defensive posture. Additionally, there is a growing focus on vendor risk management and compliance automation to address regulatory requirements across jurisdictions. This highlights several case studies that demonstrate the practical application of these advanced methodologies in various sectors, including healthcare, finance, and enterprise IT. Despite these advancements, challenges such as data sensitivity, high implementation costs, and skill gaps persist. This concludes by outlining future directions for research and practice, emphasizing the need for continuous innovation, cross-disciplinary collaboration, and the integration of emerging technologies like quantum-safe cryptography to ensure robust risk management in cloud environments. These efforts are essential to sustaining the security, resilience, and trustworthiness of modern cloud-based project infrastructures.