GromBeestje

The OAuth plugin for WordPress allows you to provide authentication against any 
OAuth provider. This plugin is uses the OAuth library by Manuel Lemos. The 
plugin allows the admin to select any from the services supported 
out-of-the-box by the said library. Additionally it is possible to configure a 
service manually, which means any site supporting the OAuth protocol can 
be used.

BlaatLogin: OAuth

This plugin turns your WordPress website into an OAuth Consumer. It allowsallows your users to sign in with any OAuth provider.

Authress

This plugin upgrades the standard WordPress login forms with one powered by <a href="https://authress.io" rel="nofollow ugc">Authress</a> that enables:
<ul>
<li>Universal authentication
<ul>
<li>Over 40 social login providers</li>
<li>Enterprise connections (SAML, Office 365, Google Apps, and more)</li>
<li>Customer configurable SSO connections</li>
</ul>
</li>
<li>Ultra secure
<ul>
<li>User identity</li>
<li>Security access policies</li>
<li>Mitigate brute force attacks</li>
</ul>
</li>
</ul>
Which includes: 
– Azure AD and B2C 
– Office 365 
– WSO2 
– Ping Identity 
– Okta 
– Auth0 
– Keyclock 
– LinkedIn 
– Salesforce 
– Twitter 
– Google Workspace 
– Yahoo 
– Salesforce 
– Hubspot 
– Steam 
– Slack 
– And any custom OAuth2.1, OpenID, or SAML provider
With SSO Login, you can automatically support business and enterprise customers that have important security requirements for their users to use your site and platform.
<h3>Technical Notes</h3>
By using this plugin you are delegating the site authentication and profile handling to Authress. That means that you won’t need to use the WordPress database to authenticate users and the default WordPress login forms will be upgraded to support the new SSO Login flow.
Please see our <a href="https://authress.io/knowledge-base/" rel="nofollow ugc">knowledge base</a> for more information on how Authress authenticates and manages your users.
<h4>Migrating Existing Users</h4>
Authress allows multiple authentication providers. You can have social providers like Facebook, Twitter, Google+, a database of users and passwords (just like WordPress), or you can use an Enterprise directories like, Office365, Google Apps, SAML, OpenID, OAuth2.1. All those authentication providers are supported and more.
<h3>How to customize this plugin</h3>
This plugin provides extension points to make it easier to configure it exactly as you need. Check out the full docs: 
* <a href="https://github.com/Authress/wordpress-sso-login/blob/main/docs/customizations.md" rel="nofollow ugc">SSO Login customizations</a>

SSO Login – Universal (OAuth + SAML)

SSO Login provides user login, business authentication, SSO, Social login, and Single Sign-On for all sites.

BlaatLogin: OAuth vs SSO Login – Universal (OAuth + SAML)