The SI unit for velocity is:

1. Velocity is a displacement divided by a time. 2. The SI base units for those are the metre and the second. 3. The SI unit for velocity is metres per second. 4. Kilometres per hour, miles per hour and centimetres per second are common but not SI. _Source: OpenStax College Physics for AP(R) Courses 2e (CC BY 4.0), Ch 2 'Kinematics', sections 2.1-2.8_