Add or create a new Lead source

Add a new Lead Source to the Lead Source picklist 

1. Select Setup.
2. Click Customize.
3. Click Leads.
4. Click Fields.
5. Click Lead Source.
6. Click on New under Account/Lead Source Picklist Values.
7. Add the New Lead Source option and if you have Record types, select the Record types where you want the new Lead Source option to be visible.
8. Click on Save.

1. Select the gear icon.
2. Select Setup.
3. Click Object Manager.
4. Click Lead.
5. Click Fields & Relationships.
6. Click Lead Source.
7. Click on New under Account/Lead Source Picklist Values.
8. Add the New Lead Source option and if you have Record types, select the Record types where you want the new Lead Source option to be visible.
9. Click on Save.

Note: If your Organization is using Record Types, you'll have to modify the Picklist values available on all of your active Record Types. 


Modify Picklist Values

1. Go to:

Salesforce Classic: Go to Setup | Customize | Leads 
Lightning Experience: Click the gear icon then go to Setup | Object Manager | Leads

2. Under "Record Types," select one record type.
3. Look for lead source under "Picklists Available for Editing," and then Click Edit.
4. Add/remove values as preferred on the selected values box.
5. Optionally set a default value.
6. Click Save.

Note: The above mentioned steps 'Modify Picklist values' on record type applies to any standard and custom object.