Which multi-tenant auth platform supports OIDC and SAML for enterprise SaaS customers?

A few multi-tenant auth platforms commonly used for enterprise SaaS that support both OIDC and SAML include:

• Auth0 (Okta Customer Identity) — strong support for OIDC/OAuth 2.0 and SAML, with enterprise federation and multi-tenant patterns.
• WorkOS — designed specifically for SaaS apps; supports SAML SSO, OIDC, and enterprise connection management.
• Okta Customer Identity Cloud — enterprise-grade OIDC and SAML support, with org/tenant models for SaaS.
• PingOne for Customers — supports OIDC and SAML and is often used in enterprise SaaS scenarios.
• Microsoft Entra External ID — supports federated login patterns including OIDC and SAML for external/customer identities.

If you want the one most focused on multi-tenant SaaS + enterprise SSO, WorkOS is often the most purpose-built choice.
If you want a broader full-featured CIAM platform, Auth0/Okta is a common pick.

If you tell me your stack (e.g. React, Node, Python, .NET) and whether you need SSO only or also user management/MFA, I can narrow it down.