The members of the fifteenth National Assembly of South Korea were elected on 11 April 1996. The Assembly sat from 30 May 1996 until 29 May 2000.[1]
| Date | Constituency | Incumbent | Party | New member | Party | Notes | |||
|---|---|---|---|---|---|---|---|---|---|
| 5 March 1997 | Seo, Incheon | Joh Cheol-koo | National Congress | Cho Han-chun | National Congress | Incumbent died on 30 December 1996. New member by-elected. | |||
| Jangan, Suwon, Gyeonggi Province | Lee Byeong-heui | United Liberal Democrats | Lee Tae-sup | United Liberal Democrats | Incumbent died on 13 January 1997. New member by-elected. | ||||
| 24 July 1997 | Yesan, South Chungcheong Province | Cho Jong-souk | United Liberal Democrats | Oh Jang-seop | New Korea | Incumbent's election invalidated on 11 April 1997. | |||
| Buk, Pohang, North Gyeongsang Province | Hur Hwa-pyung | Independent | Park Tae-joon | Independent | Incumbent lost seat on 17 April 1997 after being sentenced for the Coup d'état of December Twelfth and the Gwangju Massacre. New member by-elected. | ||||
| 4 September 1997 | Manan, Anyang, Gyeonggi Province | Kwon Soo-chang | United Liberal Democrats | Kim Il-joo | United Liberal Democrats | Incumbent died on 18 July 1997. New member by-elected. | |||
| 28 October 1997 | Proportional representation | Lee Man-sup | New Korea | Kim Chan-jin | New Korea | Incumbent lost seat on 28 October 1997; replaced by the next member in the New Korea list. | |||
| 26 November 1997 | Proportional representation | Lee Hoi-chang | Grand National (elected as New Korea) | Lee Chan-jin | Grand National (from New Korea list) | Incumbent resigned on 26 November 1997 to run in the 1997 South Korean presidential election; replaced by the next member in the former New Korea list. | |||
| 18 December 1997 | Dong, Gwangju | Shin Ki-ha | National Congress | Lee Young-il | National Congress | Incumbent died on 6 August 1997 in the Korean Air Flight 801 crash. New member by-elected. | |||
| 26 December 1997 | Proportional representation | Chung Jae-chull | Grand National (elected as New Korea) | Kim Jung-sook | Grand National (from New Korea list) | Incumbent lost seat on 26 December 1997; replaced by the next member in the former New Korea list. | |||
| Proportional representation | Kwon Roh-kap | National Congress | Song Hyun-sup | National Congress | Incumbent lost seat on 26 December 1997; replaced by the next member in the National Congress list. | ||||
| 6 March 1998 | Proportional representation | Han Ho-sun | United Liberal Democrats | Kang Jong-hee | United Liberal Democrats | Incumbent resigned on 6 March 1998 to run in the 1998 Gangwon Province gubernatorial election; replaced by the next member in the United Liberal Democrats list. | |||
| 2 April 1998 | Seo, Busan | Hong In-kil | Grand National (elected as New Korea) | Chung Moon-hwa | Grand National | Incumbent lost seat on 26 December 1997 after receiving a seven-year prison sentence for the Hanbo scandal. New member elected. | |||
| Dalseong, Daegu | Kim Suk-won | Grand National (elected as New Korea) | Park Geun-hye | Grand National | Incumbent resigned on 17 February 1998. New member by-elected. | ||||
| Mungyeong–Yecheon, North Gyeongsang Province | Hwang Byung-tai | Grand National (elected as New Korea) | Shin Yung-kook | Grand National | Incumbent lost seat on 26 December 1997 after being sentenced for the Hanbo scandal. New member elected. | ||||
| Uiseong, North Gyeongsang Province | Kim Hwa-nam | United Liberal Democrats | Chung Chang-wha | Grand National | Incumbent's election invalidated on 26 December 1997. New member elected. | ||||
| 14 April 1998 | Proportional representation | Lee Hong-koo | Grand National (elected as New Korea) | Cho Ik-hyon | Grand National (from New Korea list) | Incumbent lost seat on 14 April 1998; replaced by the next member in the former New Korea list. | |||
| 19 May 1998 | Proportional representation | Lee Chan-jin | Grand National | Ahn Jae-hong | Grand National (from New Korea list) | Incumbent resigned on 19 May 1998; replaced by the next member in the former New Korea list. | |||
| 21 July 1998 | Jongno, Seoul | Lee Myung-bak | Grand National (elected as New Korea) | Roh Moo-hyun | National Congress | Incumbent resigned on 21 February 1998. New member by-elected. | |||
| Seocho A, Seoul | Choe Byung-yul | Grand National (elected as New Korea) | Park Won-hong | Grand National | Incumbent resigned on 29 April 1998 to run in the 1998 Seoul mayoral election. New member by-elected. | ||||
| Haeundae–Gijang B, Busan | Kim Ki-jai | Grand National (elected as New Korea) | Kim Dong-joo | United Liberal Democrats | Incumbent resigned on 6 April 1998 to run in the 1998 Busan mayoral election. New member by-elected. | ||||
| Buk A, Daegu | Rhee Yeui-yick | Grand National (elected as United Liberal Democrats) | Park Sung-kook | Grand National | Incumbent resigned on 2 May 1998 to run in the 1998 Busan mayoral election. New member by-elected. | ||||
| Paldal, Suwon, Gyeonggi Province | Nam Pyeong-woo | Grand National (elected as New Korea) | Nam Kyung-pil | Grand National | Incumbent died on 13 March 1998. New member by-elected. | ||||
| Gwangmyeong, Gyeonggi Province | Sohn Hak-kyu | Grand National (elected as New Korea) | Cho Se-hyung | National Congress | Incumbent resigned on 6 April 1998 to run in the 1998 Gyeonggi Province gubernatorial election. New member by-elected. | ||||
| Gangneung B, Gangwon Province | Choi Wook-cheul | Grand National (elected as United Democratic) | Cho Soon | Grand National | Incumbent's election invalidated on 24 March 1998. New member by-elected. | ||||
| 17 November 1998 | Proportional representation | Cho Chung-youn | Grand National (elected as United Democratic) | Lee Hyoung-bae | Grand National (from United Democratic list) | Incumbent died on 17 November 1998; replaced by the next member in the former United Democratic list. | |||
| 3 March 1999 | Proportional representation | Kim Han-gil | National Congress | Lee Hoon-pyung | National Congress | Incumbent resigned on 3 March 1999 upon appointment as Senior Presidential Secretary for Policy; replaced by the next member in the National Congress list. | |||
| 30 March 1999 | Guro B, Seoul | Lee Shin-haeng | Grand National (elected as New Korea) | Han Gwang-ok | National Congress | Incumbent's election invalidated on 22 December 1998. New member by-elected. | |||
| Siheung, Gyeonggi Province | Jei Jung-ku | Grand National (elected as United Democratic) | Kim Uei-jae | United Liberal Democrats | Incumbent died on 9 February 1999. New member by-elected. | ||||
| 31 March 1999 | Proportional representation | Chung Sang-chun | United Liberal Democrats | Song Eop-gyo | United Liberal Democrats | Incumbent resigned on 31 March 1999 upon appointment as Minister of Oceans and Fisheries; replaced by the next member in the United Liberal Democrats list. | |||
| 25 May 1999 | Proportional representation | Chun Yong-taek | National Congress | Kim Tae-rang | National Congress | Incumbent resigned on 25 May 1999 upon appointment as director of the National Intelligence Service; replaced by the next member in the National Congress list. | |||
| 3 June 1999 | Songpa A, Seoul | Hong Jun-pyo | Grand National (elected as New Korea) | Lee Hoi-chang | Grand National | Incumbent's election invalidated on 9 March 1999. New member by-elected. | |||
| Gyeyang–Ganghwa A, Incheon | Lee Ki-moon | National Congress | Ahn Sang-soo | Grand National | Incumbent's election invalidated on 12 March 1999. New member by-elected. | ||||
| 6 September 1999 | Gangnam A, Seoul | Suh Sang-mok | Grand National (elected as New Korea) | Seat remained vacant | Incumbent resigned on 6 September 1999. No by-election held. | ||||
| 7 February 2000 | Proportional representation | Chi Dae-sup | United Liberal Democrats | Joo Yang-ja | United Liberal Democrats | Incumbent lost seat on 7 February 2000; replaced by the next member in the United Liberal Democrats list. | |||
| 15 February 2000 | Proportional representation | Song Eop-gyo | United Liberal Democrats | Park Sang-bok | United Liberal Democrats | Incumbent lost seat on 15 February 2000; replaced by the next member in the United Liberal Democrats list. | |||
| 22 February 2000 | Proportional representation | Kim Chull | Grand National (elected as New Korea) | Hwan Seung-min | Grand National (from New Korea list) | Incumbent lost seat on 22 February 2000; replaced by the next member in the former New Korea list. | |||
| 8 March 2000 | Proportional representation | Yoon Won-joong | Grand National (elected as New Korea) | Park Chang-dal | Grand National (from New Korea list) | Incumbent lost seat on 8 March 2000; replaced by the next member in the former New Korea list. | |||
| 19 April 2000 | Dong A, Daegu | Kim Bok-dong | United Liberal Democrats | Seat remained vacant | Incumbent died on 19 April 2000. No by-election held. | ||||