This chapter develops a practical toolkit for valuing financial institutions with opaque balance sheets, high leverage, and tight supervision. It explains why conventional discounted cash flow methods misfire, and instead emphasizes adjusted tangible book value, normalized profitability, and capital adequacy as primary anchors. The discussion integrates business model diagnostics, asset quality assessment, regulatory capital analysis, and stress-scenario modeling to link earnings power with downside resilience. A structured due diligence framework highlights red flags in credit, funding, governance, and regulation, providing practitioners with realistic valuation ranges rather than false precision. The chapter addresses fintech entrants and special situations in distressed institutions.