The type or namespace SharePointOnlineCredentials could not be found error in console application for SharePoint online

This SharePoint csom tutorial, we will discuss how to fix an error The type or namespace SharePointOnlineCredentials could not be found which comes when we create a console application for SharePoint online Office 365 sites (sharepointonlinecredentials not found).

Recently I have created a console application for SharePoint online but when I am using the below code to pass the credentials to connect to SharePoint online site it gave the below error.

clientContext.AuthenticationMode = ClientAuthenticationMode.Default;
clientContext.Credentials = new SharePointOnlineCredentials(GetSPOAccountName(), GetSPOSecureStringPassword());

The error comes as:
The type or namespace SharePointOnlineCredentials could not be found (are you missing a using directive or an assembly reference?). It looks like below:

In that console application, I have added the Microsoft.SharePoint.Client.dll (version: v14.0.4762.1000) from the NuGet package.

To resolve the issue, I have added the “Microsoft.Sharepoint.Client.Online.CSOM” from NuGet itself. You can find like below:

After this, the error (sharepointonlinecredentials not found) will not come.

You may like following SharePoint csom tutorials:

• Content type Examples using CSOM in SharePoint Online/2013/2016
• Get all lists and document libraries programmatically using CSOM in SharePoint Online
• Copy list items from one site collection to another programmatically using CSOM in SharePoint Online
• Add items from CSV file to SharePoint Online List using PowerShell in CSOM
• How to Use CAML Query for Boolean field for SharePoint 2013/2016/Online Object Model CSOM
• Create an index in SharePoint Online list using CSOM

This SharePoint tutorial helps us to solve error The type or namespace SharePointOnlineCredentials could not be found.