Arianna Fontana (ITA) is the 500m champion after a photo finish placed her ahead of Choi Min-Jeong (KOR).
Yara van Kerkhoff (NED) finished third in the race.
After the race, the judges penalized Choi for cutting the line promoting van Kerkoff and Kim Boutin(CAN) , to silver and bronze.
This is Fontana's sixth Olympic medal but her first gold. This is also her third medal in this event, winning a bronze in the 500m in Turin 2006 and a silver in Sochi 2014.
Fontana equals Wang Meng (CHN) for the most medals by a woman in short track speed skating.
Boutin, Elise Christie (GBR), Choi, van Kerkhoff, and Fontana made up the five-racer final.
Boutin was elevated to the final by the judges after a collision in her semifinal.
China, which had won the women's short track 500m at the past four Olympics, did not have a representative in the final after Fan Kexin and Qu Chunyu were penalized in the semifinals.
Marianne St-Gelais (CAN) and Maame Biney (USA) were the two biggest names eliminated in the quarterfinal stage.
St-Gelais was disqualified for a penalty after a crash.
"Sometimes things go your way and sometimes they don't," St-Gelais said to the media. "However, that's done and I have to think about the other distances. It's disappointing for sure because I don't think I deserve this call."
Biney was unable to recover from a slow start in her race.
"I lost my rhythm throughout the whole race and I couldn't find it again. Over the next four years, I'm going to try to find that rhythm and just keep going," Biney said after the race.
Men's 1000m heats
American John-Henry Krueger advanced to the 1000m quartfinals, while his teammate J.R. Celski was elminated.
Krueger jumped out to an early lead and was able to hold on the whole race.
Celski was involved in a crash that forced a restart in his heat. After the restart, Celski did not look his best and was visibly slow.
Medal favorite Seo Yi-Ra (KOR) finished third in his heat and was seemingly disqualified, but after the race the referee's determined that Han Tianyu (CHN) was eliminated, advancing Seo. The news was received with cheers from the home crowd.
Men's 5000m relay heats
China, Canada, Hungary and South Korea advance to the 5000m relay finals. The South Korean team set a new Olympic record finishing in 6:34.510.
China had set a new Olympic record in the race with a time of 6:36.605 in the previous heat.
The United States relay team finished third in their heat and move on to the B final.
- Arianna Fontana wins 500m gold
- Who is Arianna Fontana?
- How Arianna Fontana quietly skated into short track history
- Havard Lorentzen wins 500m gold, sets new Olympic record
- Olympic preview: Women's 500m
- Nao Kodaira wins 500m gold medal, ends Lee Sang-Hwa's Olympic dominance
- Wu Dajing dominates the field in 500m win
- Arianna Huffington wants to help fix our 'culture of burnout'
- Maame Biney advances to 500m quarterfinal
- Maame Biney eliminated in the 500m quarterfinal