Gangnam

A company-run branch of a sundae-gukbap (pork and blood-sausage rice soup) chain on Teheran-ro 1-gil, close to Exit 12 of Gangnam Station, open 24 hours. Sundae gukbap and pork gukbap are ₩11,000, and a one-person set with a soup plus boiled pork and sundae is ₩16,000. There is a bar counter for solo diners along the window, and you order with the QR code or tablet at your seat. Kakao Map and three September 2026 blogs all list it as open 24 hours.

A Jeonju-style kongnamul gukbap (bean-sprout soup with rice) restaurant in an alley on Yeoksam-ro 3-gil, behind Exit 4 of Gangnam Station. Kakao Map and DiningCode list it as open 24 hours every day, but a notice on Naver and an October 2026 blog say it closes from 21:00 Sunday to 09:00 Monday. The house kongnamul gukbap is ₩8,000 and the kimchi version ₩9,000 (Naver and DiningCode), which makes it one of the cheaper soup breakfasts around Gangnam Station.

An egg-sandwich shop in the basement of a building toward Exit 7 of Sinnonhyeon Station. It opens at 07:00 every day; closing is 20:30 per Naver, DiningCode and a blog but 21:00 per Kakao Map. You order at a kiosk, and the American Ham Cheese sandwich was ₩5,600 (August 2026 blog).

A haejangguk (Korean hangover soup) and beef-tripe hotpot restaurant on Teheran-ro 5-gil, toward Exit 12 of Gangnam Station. A September 2026 blog describes it as open 24 hours with no day off, while Kakao Map shows it closed from 21:30 on Sunday to 06:30 on Monday; it is open early every other morning. The signature yang-seonji haejangguk, with beef tripe and blood curd, is ₩13,000 and naejangtang (offal soup) ₩16,000. In the evening the large hall fills with people sharing hotpot over drinks.

A sourdough bakery cafe on Apgujeong-ro 14-gil, in the back streets of Garosu-gil, open 09:00–19:30 every day. That is not early, but it is two hours or more ahead of Garosu-gil brunch places such as Noras (11:00) and Pinch Brunch Bar (11:30). It is known for open toasts: almond butter open toast ₩8,000 and avocado open sandwich ₩9,800, per Kakao Map. Kakao Map and two September 2026 blogs all give the same hours.

A branch of the Isaac Toast sandwich chain in a side street (Seocho-daero 74-gil) on the Seocho side of Gangnam Station. It opens at 08:00 Monday to Saturday and is closed on Sundays, with a 14:00–17:00 break on weekdays. You order at the kiosk by the entrance; the Bacon Best toast was ₩4,500 per a July 2026 blog. A good breakfast to take away. Kakao Map and the July 2026 blog agree on the days and hours.

A kongnamul gukbap (bean-sprout soup with rice) chain branch on Sapyeong-daero by Exit 9 of Sinnonhyeon Station — one stop from Gangnam on the Shinbundang Line, or a walk up Gangnam-daero. Kakao Map and two blogs from June and July 2026 give its opening time as 07:30, so it works for breakfast. The Jeonju Nambu Market-style soup was ₩10,000 per the blogs (₩9,000 on Kakao Map's menu), and you can add squid.

A Yangpyeong-style haejangguk (hangover soup) restaurant in the basement of a building right by Exit 5 of Sinsa Station. It is open 24 hours, every day of the year (Kakao Map, Naver and DiningCode all list it so), which works for a pre-dawn meal or an early breakfast before Garosu-gil. The Yangpyeong haejangguk with blood curd and offal is ₩12,000, and haenaetang, a mix of haejangguk and offal soup, is ₩14,000. Naver and DiningCode list it as "양평신내서울해장국큰아들집".

A bagel shop on Eonju-ro 168-gil near Dosan Park, open 08:00–18:00 every day, holidays included (Kakao Map and an October 2026 blog both say so), so it is a place for a bread breakfast at 08:00 on the Gangnam side. Two blogs from September and October 2026 report getting in without the long queues it was once known for; a May 2026 blog found the indoor seats full and a line for takeaway. A plain bagel is ₩3,800 and sandwiches ₩7,500–8,500. It is a 7–10-minute walk from Exit 5 of Apgujeong Rodeo Station (Suin-Bundang Line).

A seolleongtang (ox-bone soup) restaurant on Yeoksam-ro 7-gil, toward Exit 4 of Gangnam Station, open 24 hours, every day, with no break (Kakao Map and three blogs from August to October 2026 agree). So the day and hour do not matter. Seolleongtang was ₩13,000 per an October 2026 blog (Kakao Map's menu says ₩12,000). It is about a 7-minute walk (around 430m) from the station.

A branch of the Canadian coffee-and-doughnut chain on the ground floor of Daeryung Tower, in front of Exit 5 of Gangnam Station. It opens at 07:00 on weekdays; Saturday opening is 07:00 per Kakao Map, Naver and a blog but 08:00 per DiningCode; Sundays and public holidays are 08:00. The Maple Ham & Cheese Melt is ₩6,900 and a medium Americano ₩4,000, so it suits a light breakfast of a sandwich and coffee.

A Korean-beef (hanu) haejangguk and seolleongtang restaurant about four minutes' walk from Exit 3 of Apgujeong Station. It opens early, which makes it a breakfast option on the Apgujeong and Sinsa side. Two September 2026 blogs give the opening time as 06:00 and Kakao Map as 07:00. Hanu yang-seonji haejangguk (tripe and blood-curd soup) is ₩13,000 and hanu yukhoe bibimbap (raw-beef rice bowl) ₩18,000, per Kakao Map and a blog. The blogs say it opens every day with no afternoon break.

A long-running seolleongtang (ox-bone soup) restaurant in a side street of Jamwon-dong (Seocho-gu) — across Gangnam-daero from Garosu-gil — 3–4 minutes' walk from Exit 5 of Sinsa Station, which comes up on the Jamwon-dong side. Kakao Map and two September 2026 blogs all list it as open 24 hours, every day, which makes it easy to drop by at dawn or for breakfast — but 15:00–17:00 is a break. The menu is just two items: seolleongtang at ₩15,000 and boiled beef (suyuk) at ₩52,000. Reviews say it gets busy enough at lunch to have a queue.