Slack SSO and SAML
Single Sign-On (SSO) lets your team log into Slack with the same credentials they use for all other company systems — like Google Workspace, Microsoft Azure, or Okta. Instead of managing a separate Slack password, members authenticate once through your company's identity provider and gain access automatically. SAML is the technical protocol that makes SSO work.
What SSO Solves
WITHOUT SSO
Employee manages separate passwords for each tool:
Gmail / Slack / Zoom / Jira / Salesforce / etc.
Risks: Password reuse, weak passwords,
forgotten passwords, account sharing
WITH SSO
Employee uses ONE company identity (e.g., Okta login)
→ All tools accept the same credentials
When IT deactivates one identity:
→ Access revoked from ALL connected tools instantly ✓
How SAML SSO Works
SAML SSO LOGIN FLOW
Employee opens Slack
↓
Slack redirects to your Identity Provider (IdP)
e.g., Okta, Azure AD, Google Workspace
↓
Employee enters COMPANY credentials at the IdP
↓
IdP verifies credentials
↓
IdP sends a SAML token back to Slack
↓
Slack accepts the token → Employee is logged in ✓
Employee never creates a Slack-specific password.
SAML stands for Security Assertion Markup Language. It is the industry standard protocol for SSO. Slack acts as the Service Provider (SP), and your company's identity system acts as the Identity Provider (IdP).
Supported Identity Providers
POPULAR IdPs THAT WORK WITH SLACK
Okta → Most common for mid/large companies
Microsoft Azure AD → Common in Microsoft-heavy environments
Google Workspace → Common in Google-heavy environments
OneLogin → Popular cloud IdP
Ping Identity → Common in enterprises
ADFS → Active Directory Federation Services
(on-premise Microsoft IdP)
Any SAML 2.0 IdP → Slack supports any standard SAML 2.0 provider
Setting Up SAML SSO in Slack
- Go to workspace name → Settings & administration → Workspace settings.
- Click the "Authentication" tab.
- Under "Sign in with SAML", click "Configure".
- Copy the Slack ACS URL and Entity ID — you need these for your IdP.
- In your IdP (Okta, Azure, etc.), create a new SAML application for Slack and paste those values.
- Copy the IdP metadata URL or certificate from your IdP.
- Paste it back into Slack's SAML configuration.
- Test the connection, then enable it for all members.
CONFIGURATION EXCHANGE SLACK gives you: YOUR IdP gives you: ───────────────────── ────────────────────────── ACS URL (callback URL) → Paste into IdP SAML app Entity ID (audience URI) → Paste into IdP SAML app IdP Metadata URL ← Paste into Slack settings IdP Certificate ← Paste into Slack settings
SSO Enforcement Options
OPTION BEHAVIOR
───────────────────────── ──────────────────────────────────────────────
Optional Members CAN use SSO but password login
still works as a fallback
Required Members MUST use SSO — password login
is disabled for all members
Required with exceptions SSO required, but specific accounts
(e.g., break-glass admin) can still use
password login
Automatic Member Provisioning (SCIM)
Paired with SSO, SCIM (System for Cross-domain Identity Management) lets your IdP automatically create and deactivate Slack accounts when employees join or leave the company. When HR adds a new hire in your HR system, SCIM creates their Slack account automatically. When someone leaves, SCIM deactivates their Slack access immediately — no manual admin action required.
SCIM PROVISIONING FLOW
New hire added in Okta (or Azure, etc.)
↓
SCIM syncs to Slack automatically
↓
Slack account created
Member added to default channels ✓
Employee leaves company
↓
Deactivated in IdP
↓
SCIM deactivates Slack account instantly ✓
Plan Requirements
PLAN SSO / SAML SUPPORT ──────────── ────────────────────────────────────────────── Free No SSO support Pro No SSO support Business+ SAML SSO supported Enterprise SAML SSO + SCIM provisioning + advanced controls
Benefits Summary
- Security: No Slack-specific passwords to phish or reuse.
- IT efficiency: Deactivate one account to remove access from all tools.
- User experience: One login for everything — less friction for employees.
- Compliance: Centralized authentication logs for audits.
- Onboarding speed: SCIM creates accounts instantly when employees start.
Key Takeaways
- SSO lets team members log into Slack using their existing company identity — no separate password.
- SAML is the protocol that connects Slack to identity providers like Okta, Azure AD, or Google Workspace.
- Configure SAML SSO under workspace Settings → Authentication → Sign in with SAML.
- Enforce SSO to disable password-based Slack logins entirely for stronger security.
- SCIM provisioning automates account creation and deactivation when employees join or leave.