North Korea will send 22 athletes to compete in three sports at the Winter Olympics in South Korea in February.
The two countries agreed a breakthrough deal earlier this month in the first high-level talks in two years.
The International Olympic Committee hosted a meeting in Switzerland on Saturday to discuss North Korea's participation in Pyeongchang.
IOC president Thomas Bach announced the two nations would march together at the opening ceremony on 9 February.
Describing the agreement as "a milestone in a long journey", Bach also confirmed North and South Korea will be allowed to field a unified women's ice hockey team at the Games.
North Korea will also be represented in skating and skiing.
The two countries had already agreed to compete under a unified Korean flag.
"The Olympic spirit is about respect, dialogue and understanding," Bach added following the announcement in Lausanne.
"The Olympic Winter Games PyeongChang 2018 are hopefully opening the door to a brighter future on the Korean peninsula, and inviting the world to join in a celebration of hope."
The 'Olympic Korean Peninsula Declaration' ruled:
Unified women's ice hockey - 12 players and one official from North Korea will be added to the existing South Korea squad of 23 players. The South Korean head coach will take charge but at least three players from North Korea must be selected in the team.
Figure skating - skating pair Ryom Tae-Ok and Kim Ju-Sik have been given a place, despite missing the original registration deadline.
Short track speed skating - two extra places have been allocated to North Korea, allowing Jong Kwang-Bom to compete at 1500m and Choe Un-Song to take part in the 500m.
Cross-country skiing: two male athletes - Han Chun-Gyong and Pak Il-Chol - will compete in the 15km freestyle, while one female athlete Ri Yong-Gum has a place in the 10km freestyle.
Alpine skiing: three places have been awarded - Choe Myong-Gwang and Kang Song-Il join the male competition and Kim Ryon-Hyang will compete in the women's event.
A North Korean delegation has arrived in South Korea for a landmark visit to inspect cultural venues for next month's Winter Olympics.
It is headed by Hyon Song-wol, leader of the popular Moranbong girl band and a big celebrity in the secretive state.
North Korea agreed to send a delegation to the games after the first high-level bilateral talks in two years.
The decision is seen as a diplomatic breakthrough after months of tension over its nuclear weapons programme.
Local media showed the North Korean delegation crossing the heavily-fortified border on a bus before arriving in the South Korean capital, Seoul.
Surrounded by hundreds of police officers, they then boarded a train to the eastern city of Gangneung.
But it was on Hyon Song-wol that South Korea's cameras were focused.
She and her 10-member Moranbong band are the glamorous face of North Korea - and have been described as Pyongyang's answer to the Spice Girls.
Often seen wearing miniskirts and high heels, they perform a mixture of Western-style pop and patriotic songs - in a style seen as quaintly provincial by South Koreans, AFP news agency reports.
Ms Hyon was once rumoured to have been a former girlfriend of the leader Kim Jong-un, although this has been dismissed by North Korea watchers.
She will lead the 140-member Samjiyon art troupe, which is due to give two performances - one in Seoul and another in Gangneung - during the Olympics.
The delegation's two-day visit is expected to be the first of several to prepare for Pyongyang's participation in the games.
It is the first visit by Pyongyang officials to the South for four years, reports say.
The delegation includes athletes, officials and cheerleaders.
Another team will visit the South this week to check logistics for North Korean athletes, while Seoul will send its own officials to the North's ski resort to inspect the venue.