Despite the liberalization and privatization of Malaysia’s telecommunications sector, Telekom Malaysia Berhad (TM) continues to hold a dominant position in the fixed-line market, raising concerns over the effectiveness of the Competition Act 2010. While the Act was designed to curb anti-competitive behaviour and foster a more competitive environment, TM’s near-monopoly-controlling approximately 99% of fixed-line subscriptions-persists more than a decade after the law’s enactment. This paradox highlights a critical regulatory gap in Malaysia’s competition enforcement framework. The primary objective of this paper is to assess whether TM’s market dominance in the fixed-line sector constitutes a breach of the Competition Act 2010 and to evaluate the sufficiency of current legal and regulatory measures in addressing monopolistic practices. Employing a qualitative legal research methodology, this study undertakes a doctrinal analysis of statutory provisions, case law, and policy documents, supported by a comparative perspective from international jurisdictions with similar legal structures. Findings indicate that while the Competition Act 2010 provides a broad framework to address anti-competitive conduct, enforcement in the telecommunications sector remains weak due to institutional limitations, lack of political will, and regulatory overlap. TM’s continued dominance, despite market liberalization, demonstrates the ineffectiveness of existing mechanisms to dismantle entrenched monopoly power. The paper recommends urgent reforms to enhance the enforcement powers of the Malaysia Competition Commission (MyCC), the development of sector-specific guidelines for telecommunications, and greater collaboration between regulatory bodies. Strengthening institutional accountability and ensuring transparent market oversight are essential to achieving a genuinely competitive telecommunications landscape in Malaysia.