No, lease agreements do not need to be notarized in Texas. Signatures on the lease do not need to be witnessed. In the event of an oral lease, there needs to be some written summary of the agreement, even if it is not a formal lease.
The landlord and tenant can agree to have the lease notarized for additional legal protections, but it is optional.
The information for this answer was found on our Texas Residential Lease Agreement answers.