Yes, you can control the motor speed of some parts by changing the configuration to Analog. This configuration allows you to set the speed using analog values from -10 to 10 V.
Check which parts include Analog configuration here:
https://docs.factoryio.com/manual/parts/
You can select a part configuration from the context menu (by right-clicking on the part):
https://docs.factoryio.com/manual/edit-and-run/index.html#configuration