| Acronym | Meaning |
| RCS | Radar Control Ship (US Navy) |
| RCS | Radar Countermeasures System |
| RCS | Radar Cross Section |
| RCS | Radio Communications System |
| RCS | Radio Conference Subcommittee |
| RCS | Rainwater Catchment System |
| RCS | Range Control Squadron |
| RCS | Reactor Containment System |
| RCS | Reactor Coolant System |
| RCS | Recruiting Squadron |
| RCS | Régiment de Commandement et de Soutien (French: Regiment Command and Support) |
| RCS | Regional Control of Shipping |
| RCS | Regulated Commodity Service |
| RCS | Regulations, Codes and Standards |
| RCS | Regulatory Compliance Services |
| RCS | Remote Cloud Sensing |
| RCS | Report Card Score (various organizations) |
| RCS | Requirement Control Symbol |
| RCS | Requirements Computation System |
| RCS | Research Career Scientist (US VA) |
| RCS | Réseau de Contrôle de Surveillance (French: Network Control Monitoring; environmental monitoring) |
| RCS | Reserve Component Site |
| RCS | Resident Classification Scale (Australian Department of Health and Aging) |
| RCS | Residential Care Services |
| RCS | Resource Control System |
| RCS | Revenue Cutter Service (precursor to US Coast Guard) |
| RCS | Roll Control System (Aerospace) |
| RCS | Royal Corps of Signals |
| RCS | Runway Control Structure |