Access to affordable and trustworthy financial services remains limited for billions of people worldwide, particularly in low-resource countries. Peer-to-peer (P2P) microlending has emerged as a promising approach to help bridge this gap by directly connecting borrowers and lenders without reliance on traditional financial intermediaries. However, conventional P2P microlending platforms face persistent challenges related to user trust, data privacy, and institutional dependence; issues that hinder their broader adoption and impact. This study investigates the potential of blockchain technology to address these limitations by enabling decentralized, transparent, and privacy-preserving microlending systems. Through a systematic literature review, we analyzed 35 papers in the final dataset existing work at the intersection of blockchain, P2P lending, microfinance, and financial inclusion. The findings suggest that blockchain technology can enhance trust through transparent record-keeping and programmable smart contracts, while supporting privacy via technical approaches (e.g., zero-knowledge proofs). However, implementation requires careful attention to socio-technical conditions, including governance, user literacy, and system interoperability. We propose a research agenda that focuses (1) on foundational blockchain-related challenges and (2) on platform design and real-world deployment. Our study offers conceptual grounding and practical direction for future research on inclusive, secure, and context-sensitive financial technologies.