The rapid expansion of digital commerce has transformed trademarks from traditional market identifiers into valuable online assets, making their protection in cyberspace increasingly significant. Domain names, originally created as technical internet addresses, now function as commercial identifiers closely associated with business identity, goodwill, and consumer trust. This evolution has given rise to new forms of trademark misuse, particularly cybersquatting, deceptive domain registrations, and online passing off. The borderless and anonymous nature of the internet creates complex legal challenges relating to jurisdiction, enforcement, identification of infringers, and the application of territorial trademark laws. This paper critically examines the legal issues surrounding trademark infringement in cyberspace, with particular focus on domain name disputes and the doctrine of passing off. It analyzes the conceptual relationship between trademarks and domain names, explores judicial developments in India and comparative international approaches, and evaluates dispute resolution mechanisms such as the Uniform Domain Name Dispute Resolution Policy (UDRP) and national remedies under trademark law. The study further identifies emerging enforcement challenges, including intermediary liability, trans-border reputation, and evolving digital modes of infringement. It concludes that while judicial innovation and regulatory mechanisms have strengthened trademark protection in the digital environment, effective enforcement requires harmonized international standards, stronger intermediary accountability, and adaptive legal interpretation to safeguard trademark rights in the evolving digital economy