Alpha male

a male animal having the highest rank in a dominance hierarchy:
Studies show that in spite of their high rank, access to females, etc., baboon alpha males experience a great deal of stress.
the most dominant, powerful, or assertive man in a particular group:
the alpha male of investment bankers.
Contemporary Examples

Yahoo is merely hooking up with the most alpha male company it can still find in order to survive.
Microsoft’s Prison Yard Conquest Douglas Rushkoff July 28, 2009

Football is the most American of sports, the alpha male of games.
The Opt-Out Economy Daniel Gross December 15, 2013

Werner has also taken to living closely with his wolves, behaving as an alpha male to earn their acceptance and respect.
Meet Germany’s Wolf Man Justin Green January 28, 2013

He is very cautious around Richard Parker, but he quickly asserts himself as the alpha male and marks his territory on the boat.
‘Life of Pi’: Comparing Ang Lee’s Film With Yann Martel’s Novel Mike Munoz November 20, 2012

Logline: An alpha male satellite radio host must share air time with a feminist blogger/podcaster.
TV Preview: Snap Judgments of 2012-13’s New Shows Jace Lacob, Maria Elena Fernandez June 11, 2012

Former RSD instructor Nathan Kole says he saw firsthand how this “alpha male” marketing can damage students.
The Secret World of Pickup Artist Julien Blanc Brandy Zadrozny November 30, 2014

In recent years, Montana has been electing a certain breed of burly, alpha male Democrats.
Meet Montana’s Nose-Ringed Candidate for the U.S. Senate Ben Jacobs August 14, 2014

noun
the dominant male animal or person in a group
noun

a domineering man; the dominant member in a group of males, esp. animals
Examples

Alpha male traits have been widely seen recently in American politics.
Word Origin

from first letter of the Greek alphabet, often used as an adjective to describe males and females of species who rank first in a group