For the organization at large, it is the chief executive who owns the culture. The larger the organization, the more cultures multiply. From department to department, cultures can be quite different, depending on the department leader. In any case, the leader of the organization ultimately owns the organizational culture.
It is the duality of individual-initiated and business-led courage that creates an optimal formula for progress. The courage to identify a pivot, and the freedom to be able to see that change through, is what's required to show up differently. And if you're lucky, like I am, that is exactly the culture of the company you work for. If you have that freedom, here are my recommendations to be courageous within it.