| Simon, Hannah | Board of Youth Services, 2019 | Boards & Commissions | | |
| Stange, Eric | Historical Commission | Boards & Commissions | | |
| Schaefer, Dianne | Historical Commission | Boards & Commissions | | |
| Stevens, Nathaniel | Conservation Commission | Boards & Commissions | | |
| Schlichtman, Paul | Building Committee (PTBC), School Committee Liason | | | |
| Smith, Scott | Bicycle Advisory Committee (ABAC), 6/30/2025 | | | |
| Stein, Miriam | Human Rights Response Coordination Team | Boards & Commissions, Town Manager | | |
| Swaim, Dave | Human Rights Response Coordination Team | Boards & Commissions, Town Manager | | |
| Svenson, Carol | Master Plan Advisory Committee | Boards & Commissions, Town Manager | | |
| Smith, Scott | TAC, Pct 1-7 Rep, Bicycle Advisory Liaison | Boards & Commissions, Town Manager | | |
| Stamps, Susan | Tree Committee, 12/2025 | Boards & Commissions, Town Manager | | |
| Strassburger, George | Local Emergency Planning Committee, AEMA | Boards & Commissions, Town Manager | | |
| Shah, Kristine | Local Emergency Planning Committee, Council on Aging | Boards & Commissions, Town Manager | | |
| Sheppard, Patricia | Local Emergency Planning Committee, Chief Technology Officer | Boards & Commissions, Town Manager | | |
| Stubbe, James | TAC, Member At Large | Boards & Commissions, Town Manager | | |
| Swan, Laura | TAC, School Committee Liaison, Chair | Boards & Commissions, Town Manager | | |
| Stein, Leland | Parking Advisory Committee, Arlington Center Merchant | Boards & Commissions, Town Manager | | |
| Sawtelle, Steven | Veterans Council (1/31/2018) | | | |
| Slotnick, Larry | Zero Waste Arlington | | | |
| Susse, Jennifer | Finance Committee (Prct. 3, 2024) | | | |
