How to Connect a Facebook & Yahoo Accountby Kirk Bennet
If you want to share your Yahoo updates with your Facebook account, you can link your Yahoo and Facebook accounts. Yahoo makes it easy to link the two accounts. However, the content you share from Yahoo with Facebook must adhere to Facebook's Terms of Service. Similarly, if you select to import content from Facebook to Yahoo, the content must adhere to Yahoo's Terms of Service. You can unlink the Yahoo and Facebook accounts later if you no longer want to share content between the two accounts.
Navigate to the Yahoo Profile website (link in Resources) and log in using your Yahoo ID and password.
Click the "Gear" icon to navigate to the Settings page.
Click "Connect my Facebook account" in the Connected Accounts section of the Settings page.
Click the "Facebook" icon to open the Facebook login window.
Enter your Facebook email and password in the "Email or Phone" and "Password" fields and click "Log In" to log in to your Facebook account. A "Linking to Facebook account" message is displayed until the two accounts are linked. The status in the Linked Accounts section on Yahoo is changed to "Connected as...".