<p>In recent years, Environmental, Social, and Governance (ESG) and Corporate Social Responsibility (CSR) have risen to prominence as key elements in corporate strategies and policy discussions worldwide. These frameworks are increasingly central to firms seeking to meet contemporary expectations for sustainability and ethical business practices. This systematic review maps the discourse on the nexus between CSR/ESG practices and corporate performance and synthesizes an emerging knowledge-economy stream showing that ESG/CSR can function as knowledge assets by strengthening intellectual capital, fostering green innovation, and accelerating digital transformation and data transparency. Drawing on 150 studies across 78 peer-reviewed journals published between 1994 and 2025, the review identifies prevailing themes, pinpoints literature gaps, and proposes directions for future research. The evidence suggests that CSR and ESG, once viewed as peripheral, have become integral to corporate strategy, influencing outcomes ranging from financial performance and investor behavior to knowledge creation. Our synthesis reveals a central theoretical tension: while a dominant stream supports ESG/CSR as a knowledge-generating asset that strengthens intellectual capital and accelerates green innovation, another stream reports conflicting evidence consistent with symbolic adoption and measurement noise, where ESG primarily improves disclosure optics rather than capability building. We show that these inconsistencies are partly reconciled when ESG/CSR is examined through a Knowledge-Based Economy (KBE) lens that emphasizes intangible assets, learning, and digital verification infrastructure. Despite advances, significant questions remain unresolved, underscoring the need for further research on when and how sustainability initiatives translate into measurable value across industries and regions.</p>