Zoro is the vice captain of the Straw Hat Pirates and officially is the combatant and has vice captain like role in the crew (according to the recent Databooks). It’s almost a given now that Zoro has Conqueror’s Haki and is accepted widely by the One Piece community.
So here I’ve listed some of the reasons of why I feel Zoro does in fact have Conqueror’s Haki.
1- Zoro has an indomitable will which has been seen throughout the series right from his introduction scene, and will only bow down for the sake of his captain.
2-The most obvious one, because Rayleigh who was the vice captain of the Pirate King also has it and there are many parallels in both of their characters and interactions.
3-Katakuri who’s like the right hand man of Big Mom also has it.
4-Mihawk most certainly has Conqueror’s Haki. Why? Because he was the rival of one of the strongest characters in the series with arguably the strongest Haki and who has the biggest feat of Conqueror’s Haki seen in the series. It’s important to note that Mihawk lost interest in Shanks after he lost his arm (meaning it wasn’t Shanks who stopped after becoming a Yonko). Their clashes were heard throughout the New World as stated by Whitebeard himself. This could mean that Mihawk and Shanks fought imbuing strong Conqueror’s Haki in their swords (as seen by the clash of Whitebeard and Shanks). Mihawk is the world’s strongest swordsman which effectively makes him “the King” of swordsmen.
5-Zoro has to defeat Mihawk to fulfill his dream of being the World’s Strongest Swordsman so he should have Conqueror’s Haki as well.
6-On Fishman Island after witnessing Luffy’s feat of Conqueror’s Haki he was the only Straw Hat who wasn’t surprised and rather stated that if Luffy wasn’t capable of this he might have to step down as the captain.
7-Zoro has been stated to have an intimidating aura and has been stated to be the vice captain by Urouge and Bartolomeo. Bartolomeo is a Straw Hats nerd and follows the group throughout knowing all the minute details about their adventures which are kept hidden from the world. So even if he stated that Zoro is a vice captain on his own discretion, it most certainly is what the world thinks and is true. So here’s all I have to say, and I strongly feel that Zoro is a one in a million type of personality and is infact gifted by the heavens.