Most projects will have an Executive Sponsor. In Prince 2 terms I am referring to the ‘Executive’ and in PMBOK language this is the ‘Sponsor’. This is the person who (a) has the funds to pay for the project to go ahead and (b) is the person who will or should champion your project.
This person is very important to your project. They are the person that should be providing the face of your project at a senior level, making key decisions along the way based on their business knowledge and be very supportive of the team in such a way as to help the team sustain momentum along the delivery journey.