What is the relationship between SOLID and Clean Architecture?

Clean Architecture (Robert C. Martin) is the macro-level architectural pattern that embodies all five SOLID principles simultaneously. Its concentric ring structure enforces: SRP — each ring (Entities, Use Cases, Interface Adapters, Frameworks) has a distinct responsibility; OCP — inner rings are closed to changes from outer rings; LSP — outer rings implement interfaces defined by inner rings, and must be behaviorally substitutable; ISP — boundaries between rings are defined by narrow, role-specific interfaces (input/output ports); DIP — the Dependency Rule (all dependencies point inward) is DIP applied structurally — outer layers depend on inner abstractions, never the reverse. Clean Architecture is essentially SOLID principles applied at the architecture level, creating systems where frameworks, databases, and UIs are implementation details that can be swapped without affecting the core business logic.