Roman Sergeyevich Kostomarov (born 8 February 1977) is a Russian ice dancer. With partner Tatiana Navka, he is the 2006 Olympic champion, two-time World champion (2004–05), three-time Grand Prix Final champion (2003–05), and three-time European champion (2004–06).
Kostomarov began skating at the age of nine and a coach put him in ice dancing at eleven. He won the 1996 World Juniors Championships with Ekaterina Davydova.
Kostomarov began competing with Tatiana Navka during the 1998–99 season. They were coached by Natalia Linichuk. They won the bronze medal at the Russian Championships and were sent to the World Championships in their first season together, placing 12th. Linichuk then dissolved the team and paired Kostomarov with Anna Semenovich. He competed with Semenovich during the 1999–2000 season.
In mid-2000, Kostomarov called Navka and asked to skate with her again. They were coached by Alexander Zhulin in New Jersey. Navka/Kostomarov won the World title in 2004 and again in 2005. They also won three European titles from 2004–2006. They then won gold at the 2006 Winter Olympics in Turin, Italy. Navka/Kostomarov retired from competition after the Olympics but continue to skate in shows together.
Kostomarov has skated with celebrity partners in Russian ice shows such as Ice Age.
Kostomarov married Austrian ladies' champion Julia Lautowa in June 2004. Their relationship ended in divorce. In April 2014, he married Russian ice dancer Oksana Domnina. Their daughter, Anastasia, was born on 2 January 2011. Their son, Ilya, was born in January 2016.