Do I need to disclose my arrest?

Yes, you will need to report the arrest. They will find it anyway and then you look untruthful. Dishonesty will doom your chances of success in the instance.

Duplicate question (duplicate / same answer): If your case was expunged and you have not other arrests then you can deny it pursuant to the following guidelines: Entities That Get Sealed And Expunged Records: The subject of a criminal history record sealed under this section or under other provisions of law, including former s.893.14, former s.901.33, and former s.943.058, may lawfully deny or fail to acknowledge the arrests covered by the sealed record, except when the subject of the record: Is a candidate for employment with a criminal justice agency; Is a defendant in a criminal prosecution; Concurrently or subsequently petitions for relief under s.943.0585 or s.943.059; Is a candidate for admission to The Florida Bar; Is seeking to be employed or licensed by or to contract with the Department of Children and Family Services, the Division of Vocational Rehabilitation within the Department of Education, the Agency for Health Care Administration, the Agency for Persons with Disabilities, the Department of Health, the Department of Elderly Affairs, or the Department of Juvenile Justice or to be employed or used by such contractor or licensee in a sensitive position having direct contact with children, the disabled, or the elderly; Is seeking to be employed or licensed by the Department of Education, any district school board, any university laboratory school, any charter school, any private or parochial school, or any local governmental entity that licenses child care facilities; or Is attempting to purchase a firearm from a licensed importer, licensed manufacturer, or licensed dealer and is the subject to a criminal history background check under state or federal law. Please see: http://www.fdle.state.fl.us/Content/getdoc/57ba1587-6592-4ca4-9560-2738f67ba2ae/Agencies-that-are-Entitled-to-Sealed-Expunged-Info.aspx I hope that I have been helpful in answering your question.

I'm pretty sure you can answer "no" since your case was fully expunged and have no other arrest on your record.

You did not tell us what state your arrest was in but since you are in Florida I will answer as if the case happened in Florida. First of all, participating in the Pre-trial Diversion Program and having the case dismissed does NOT automatically expunge your record. You must apply for expungement through FDLE. It is a fairly lengthy and detailed procedure. If the case is really expunged you are legally allowed to "lie" and say you have not been arrested except for the situations listed by the first response. My advice is to first make sure your case was truly expunged before going any further.

I agree with the other answers. You say that the case was "fully expunged". Do you have an expunction order signed by a judge? If not your case likely was not expunged. It is pretty easy to find out if it was or not. Contact the Clerk of Court either directly or via their website and put your name in and see if they have a record of it. If expunged you can generally legally deny the arrest that corresponds with that case with certain exceptions that should be listed in the order and are otherwise listed in the statute.