This gives an overview of STM32 MCUs for which RIOT has at least basic support.
As ST releases new Chips we are not always up to date with the changes needed to support them, but they typically share a lot of code.

High Performance

• STM32F4
• STM32F7
• STM32H5
• STM32H7
• STM32N6

Mainstream

• STM32C0
• STM32C5
• STM32F0
• STM32F1
• STM32F3
• STM32G0
• STM32G4

Ultra Low Power

• STM32L0
• STM32L1
• STM32L4
• STM32L4+
• STM32L5
• STM32U0
• STM32U3
• STM32U5

Wireless

• STM32WB
  • IEEE 802.15.4 radio
  • BLE radio
• STM32WL
  • LoRa radio

Useful links

https://www.st.com/en/microcontrollers-microprocessors/stm32-32-bit-arm-cortex-mcus.html