The list is based on cable television with average ratings of all the episodes in each drama series. The data changes every time a new record has hit the target. All reached rankings for average nationwide TV ratings come from Nielsen Korea. Each drama series ratings are taken from all episodes during their broadcast.
1. "The World of The Married" (2020) - 18.8%
Channel: JTBC
Air Schedule: Fridays & Saturdays
No. of Episodes: 16
Director: Mo Wan-il
Writer: Joo Hyun
The JTBC drama maintained its high ratings from premiere broadcast to its final episodes. Viewers got mixed emotions as the show ran for weeks, plus the show became record-breaking as the highest-rated drama premiere for JTBC!
"The World of The Married" tackles marriage, divorce, and self-realization. Stars Kim Hee Ae, in character as a famous doctor, thought her marriage was perfect until things changed when her husband (Park Hae Joon) commits adultery. Their struggles didn't only affect their marriage but the people that surrounded them, especially their child.
2. "Mr. Sunshine" (2018) - 13.0%
Channel: tvN
Air Schedule: Saturdays & Sundays
No. of Episodes: 24
Director: Lee Eung-bok
Writer: Kim Eun-sook
"Mr. Sunshine" achieved high ratings of 18.1%, thus, becoming one of the top Korean dramas in 2018. It's one of Sky Castle's rivals during the 55th Baeksang Arts awards in many categories.
The story revolves around a man (Lee Byung Hun) who grew up in the US and returned home to Korea as an American Marine Corps officer. As he returns to his homeland, he meets a noblewoman (Kim Tae Ri) and falls in love with her.
3. "Goblin" (2016-2017) - 12.9%
Channel: tvN
Air Schedule: Fridays & Saturdays
No. of Episodes: 16
Director: Lee Eung-bok
Writer: Kim Eun-sook
This fantasy-romance drama became a hit series globally, having recognized and received critical reviews from overseas fans. The story is quite interesting as a goblin (Gong Yoo), who wishes to end his cursed immortal life, gets help from his human bride (Kim Go Eun). Because of the drama's success, Kim Eun Sook, the writer of the series and also renowned in the industry, won the Grand prize at the 53rd Baeksang Arts Awards, while actor Gong Yoo won the Best Actor.
4. Sky Castle (2018-2019) - 12.5%
Channel: JTBC
Air Schedule: Fridays & Saturdays
No. of Episodes: 20
Director: Jo Hyun Tak
Writer: Yoo Hyun-mi
Sky Castle premiered at a slow start with 1.7%, but it skyrocketed to 23.8% during its finale. The drama differs in terms of peak ratings. It's the highest-rated Korean drama.
The story is about a group of affluent families (Yum Jung Ah), living in an elite neighborhood. They are determined to send their children to the popular medical school in the country.
5. Reply 1988 (2015-2016) - 12.4%
Channel: tvN
Air Schedule: Fridays & Saturdays
No. of Episodes: 20
Director: Shin Won Ho
Writer: Lee Woo Jung
It's a story of simple and ordinary five teenagers, living in the same neighborhood, and have been friends since they were kids. It depicts the reality of events that tackles friendship, love, and family. It hit a peak rating of 18.8% during its premiere broadcast for its record viewership.
Actress and K-pop star Hyeri, Park Bo Gum, Ryu Jun Yeol, Go Kyung Pyo, and Lee Dong Hwi starred in this series. And because of its amazing storyline and the cast members' outstanding portrayals, "Reply 1988" received at least eight nominations and a Best Director and Best New Actor at the 52nd Baeksang Arts Awards.
