| Local Name | Galaxy M21s |
| Technology | GSM / HSPA / LTE |
| 4G Bands | 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 20, 26, 28, 38, 40, 41, 66 |
| 3G Bands | HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100 |
| 2G Bands | GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2 (dual-SIM model only) |
| Speed | HSPA, LTE-A |
| Announced | 2020, November 06 |
| Status | Available. Released 2020, November 06 |
| Dimensions | 159.2 x 75.1 x 8.9 mm (6.27 x 2.96 x 0.35 in) |
| Weight | 191 g (6.74 oz) |
| Build | Glass front (Gorilla Glass 3), plastic back, plastic frame |
| SIM | Single SIM (Nano-SIM) or Dual SIM (Nano-SIM, dual stand-by) |
| Display Type | Li-Po 6000 mAh, non-removable |
| Screen Size | 6.4 inches, 100.5 cm2 (~84.1% screen-to-body ratio) |
| Resolution | 1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density) |
| Protection | Corning Gorilla Glass 3 |
| OS | Android 10, One UI 2.5 |
| Chipset | Exynos 9611 (10nm) |
| CPU | Octa-core (4x2.3 GHz Cortex-A73 & 4x1.7 GHz Cortex-A53) |
| GPU | Mali-G72 MP3 |
| Card Slot | microSDXC (dedicated slot) |
| Internal Memory | 64GB 4GB RAM, 128GB 6GB RAM | eMMC 5.1 |
| Camera Features | HDR |
| Video | 1080p@30fps |
| Loudspeaker | Yes |
| 3.5mm Jack | Yes |
| WLAN | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct |
| Bluetooth | 5.0, A2DP, LE |
| NFC | No |
| Radio | FM radio |
| USB | USB Type-C 2.0 |
| Sensors | Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass |
| Colors | Blue, Black |
| SAR EU | 0.48 W/kg (head) 1.13 W/kg (body) |
