The digitalization of transactions and communications has positioned digital signatures and electronic evidence at the core of legal and commercial systems globally. This article provides a comprehensive overview of the legal recognition, technological foundation, and admissibility of digital signatures, alongside the role of electronic evidence in judicial processes. Drawing from jurisdictions such as the United States (ESIGN Act), European Union (eIDAS), India (IT Act), and China (Electronic Signature Law), the analysis highlights the global divergence and harmonization efforts in legal frameworks. It examines the admissibility standards of digital records, issues of authenticity, integrity, chain of custody, and the impact of encryption and privacy laws. With the rising volume of digital litigation, courts increasingly rely on emails, metadata, social media, and system logs. This paper also discusses best practices for secure digital signature implementation and evidence preservation. It concludes by exploring emerging trends, including blockchain, AI analysis, and cross-border legal cooperation, as critical enablers of trust and efficiency in a digital legal ecosystem.