decision-maker
US /dɪˈsɪʒ.ənˌmeɪ.kər/
UK /dɪˈsɪʒ.ənˌmeɪ.kər/

1.
a person who makes decisions, especially important ones, in an organization or group
:
•
The final decision-maker for this project is the CEO.
•
We need to get approval from the key decision-makers before proceeding.