SOQL Query to Get the CreatedBy and LastModifiedBy User Name

Below SOQL query can be used to get the CreatedBy and LastModifiedBy User Name

SELECT Id, Name, CreatedBy.FirstName, CreatedBy.LastName, CreatedBy.Name, LastModifiedBy.FirstName, LastModifiedBy.LastName, LastModifiedBy.Name FROM Object__c

Note: Object__c, you can replace for the object you want to get these data.