| Staff | Title | Departments | Phone | Email |
|---|
| Motor Vehicle | Main Line | Tax Assessor/Collector | (361) 888-0459 | |
| Munguia, Diana | Elections Manager | County Clerk | (361) 888-0580 | |
| Mumphord, Valerie | Administrative Secretary | Constable Precinct 1 | | |
| MetroCom | | Sheriff | (361) 826-2900 | |
| Martinez, Velma | Chief Deputy | Tax Assessor/Collector | (361) 888-0204 | |
| McCoy, Timothy J. | Judge | County Court at Law 5 | | |
| McCauley, Michael | Judge | 28th District Court | | |
| Morales, Connie | Court Manager | JP 2-2 | (361) 937-2614 | |
| Main Line - Elections | | County Clerk | (361) 888-0580 | |
| McClure, C. | Deputy | Sheriff | (361) 887-2248 | |
| Molina, Melinda | Court Clerk | 319th District Court | (361) 888-0642 | |
| Medary, Missy | Judge | 347th District Court | | |
| Martinez, Rick | Bailiff | 148th District Court | (361) 888-0739 | |
| McClure, Christina | Lieutenant | Constable Precinct 2 | | |
| McCahan, Jason | Constable | Constable Precinct 2 | (361) 937-6306 | |
| Moreno, Ernest | Corporal | Constable Precinct 1 | | |
| Munoz, Armando | Deputy | Constable Precinct 1 | | |
| Muniz, Mandy | Deputy | Constable Precinct 1 | | |
| Morrison, Sue | A/P Accounting Assistant | County Auditor | (361) 888-0614 | |
| Mendoza, Oscar | Constable | Constable Precinct 5 | (361) 767-5204 | |