I am a landlord in Florida, and drafting up a Lease Agreement for my tenant. Am I legally required to have a witness sign the lease?

There is no legal requirement to have a witness for a lease contract. But to reduce the possibility of future disagreements over who actually signed the lease it's a good idea to have a witness if you and the tenant are together when you both sign (and be sure to see photo ID), or require a notary public if you're not together when signing.