How do you indicate on an application that you are still employed at one job while you are looking for another?

In the section of the application that requests your job history, you would indicate your current job at the top with the dates of employment being [start date] - present . Sometimes, you don't want a prospective employer to call your old job for a reference check because this will advise them that you are looking for a job. Simply mention that preference on your application. (They will eventually call, but only if you are bing offered the position). Also, if you are leaving on very bad terms with your current employer, it may be just a better idea to not mention them on your application at all. Good luck!