In today’s entrepreneurial landscape, social media has transformed how businesses grow and succeed. This entry explores how social capital (the networks and norms enabling cooperation) and social effectiveness (the ability to navigate and influence these networks) intersect to drive entrepreneurial success. Drawing on recent studies, it examines the dimensions of social capital (bonding, bridging, and linking) and highlights how entrepreneurs might leverage these relationships to access resources, innovate, and build resilience. Social effectiveness, encompassing emotional intelligence, political acumen, and digital communication skills, is shown as a critical multiplier of social capital, especially in the digital era where traditional face-to-face cues are diminished. Case studies such as Patagonia, Glossier, and The Honest Company illustrate how authenticity and trust-building translate online engagement into sustainable business growth. The entry also discusses challenges such as digital fatigue, performative authenticity, and equity gaps in access to influential networks. Findings from this research demonstrate that by aligning social capital with social effectiveness, entrepreneurs can strategically navigate the opportunities and risks of social media to create enduring success.