Kingdom is a 2019 South Korean TV series written by Kim Eun-hee and directed by Kim Seong-hun. It is Netflix's second Korean original series.
Kingdom is set in the real-life Joseon dynasty (also transcribed as Chosŏn or Chosun, Korean: 조선; officially the Kingdom of Great Joseon) which was founded by Yi Seong-gye in July 1392 and was replaced by the Korean Empire in October 1897. The costume design of this TV series is based on real Joseon fashion during the day.
You will find various hats worn by the actors in Kingdom. Hats in Joseon dynasty normally represented social classes. Here are some of hats worn by men in Joseon period. For hats for women, please refer to this article.

Korean traditional hats of Joseon dynasty
'Gat' worn by noblemen
The representative hat of the Joseon Dynasty is 'gat'. (The pronunciation of "gat")

It was made of horsehair, bamboo (?), silk, cow's tail hair, or raw silk.
Black gat (흑립; 黑笠)
A black gat or heungnip was restricted to men who had passed the gwageo examination.

At the 2nd Permanent Exhibition hall of the National Folk Museum of Korea in Gyeonggikdo, you can see a very wide hat.

White gat (백립; 白笠)
A white gat or baeknip was worn at the time of a national funeral.


Cinnabar red gat (주립; 朱笠)
It's worn by military officers in Joseon dynasty. The red gat (painted in red lacquer) or joorip is the same as the black gat (painted in black lacquer.)



'Straw hat' worn by youths
A straw hat or chorip (초립; 草笠) was worn by boys until a coming-of-age ceremony.
A boy wearing a straw hat is found among noblemen wearing 'gat' in a painting by Sin Yun-bok, a 19th-century Korean painter.

'Paeraengyi' worn by low-class men
Paeraengyi ('패랭이') was normally used by low-class people.

When those who wore Paeraengyi met a nobleman wearing a black gat, they had to bow to him.
Jeongjakwan
A jeongjakwan (정자관; 程子冠) is a hat of a Confucian, which is found on the five thousand Won note. Noblemen used a dongpakwan (동파관; 東坡冠), sabangkwan (사방관; 四方冠) in a rectangular shape, or choongjeongkwan (충정관; 冲正冠) besides a jeongjakwan whatever they wanted. A jeongjakwan was worn indoors while a black gat was used when going out.



Tang-geon (Horsehair skullcap) worn only by government officials
Only government officials were able to wear a horsehair skullcap or tang-geon.
Gamtoo (Horsehair cap) similar with tang-geon
Gamtoos were normally worn by gentry who were rich.
Ikseongwan worn by the King and Crown Prince
Kings wore an ikseongwan (익성관; 翼蟬冠) from which a shape of cicada wings are hung. ("Ikseong" means "cicada wings.)


Crown
The king's hat should be special due to his social status. Crown was used by the king and crown prince for ceremonies, weddings, and other big events.

Samo (Official Hat)
Since the era of King Sejong, civil and military officials wore an official hat or samo (사모; 紗帽) while they were on duty. Later, common people were able to wear a samo at a wedding ceremony. Today, people who chose a traditional wedding ceremony, a bridegroom wears a samo.



Jeollip worn by military officers
A jeollip (a solider's felt hat) was worn by military officers.


This hat began to be worn in the northwestern region of Korea and was spread to nationwide after Imjin Waeran (1592–1598) and Second Manchu invasion of Korea (1636) occurred.
* There are also helmets worn in a war.
Yougun (유건; 儒巾) worn by a student of Confucianism
This hat was worn by students of Confucianism at Sungkyunkwan.

Gulgeon (굴건; 屈巾)
It's a hat worn on top of a hempen hood by the chief mourner.

Conical hat
Used primarily as protection from the sun, snow and rain.

Hat cases
Hats described above are basic ones for men. They were stored in a hat case to prevent from being damaged.
You can purchase Korean traditional hats from Amazon.com:
Korean Traditional Hat God Korean Hat in The Kingdom Movie Is Sold at Amazon
For hats for women in Joseon era, please see the following:
Women’s hats in Joseon Dynasty – Korean traditional clothing
The official production of Kingdom Season 2 started in February 2019:
A Shooting Location of Season 2 of Netflix’s KINGDOM: Mungyeong Saejae
Some reviews on Netflix's Kingdom:


