Magnate
Etymology
From Late Latin "magnas" (plural "magnates"), meaning "great men," from "magnus" (great) — the same root as "magnify" and "magnificent." It first named the great nobles of a realm before shifting to the great powers of commerce.
noun · /MAG-nayt/
A person of great wealth and power, especially in a particular industry.
What it names
A titan of business — the oil, shipping, or media baron who dominates a whole field.
Example
The newspaper was bought by a media magnate with holdings on three continents.
Related idea
A magnate is defined by industrial dominance; a tycoon (from Japanese "taikun," great lord) is a near-synonym with a brasher, more self-made flavor.