Texas Local Government Code - LOC GOV'T § 22.032. Qualifications of Members of Governing Body

(a) To be eligible for the office of mayor of the municipality, a person must be a registered voter and must have resided within the municipal limits for at least the 12 months preceding the election day. For purposes of this subsection, residency in an area while the area was not within the municipal limits is considered as residency within the limits if the area is a part of the municipality on election day.

(b) To be eligible for the office of alderman of the municipality, a person must be a registered voter and must reside on election day in the ward from which the person may be elected.