Ömer Aşık began his basketball career in the youth system of Fenerbahçe. During the 2005–06 season, he was loaned to FMV Işık Spor. In the 2006–07 season, he signed with Alpella Istanbul. In December 2007, he transferred to Fenerbahçe Ülker and won the Turkish Basketball League (TBL) championship in the 2007–08 season. He also played in the Turkish All-Star games during this period.

^{Ömer Aşık} (AA)

• Chicago Bulls (2010–2012, 2017–2018): He started his NBA career in 2010 with the Chicago Bulls. In his first two seasons, he stood out for his defense and rebounding contributions. He returned to the Bulls for a brief period during the 2017–18 season.
• Houston Rockets (2012–2014): In the 2012–13 season, he played as the starting center for the Houston Rockets and appeared in all 82 games. He averaged 10.1 points and 11.7 rebounds that season, marking the most productive period of his NBA career.
• New Orleans Pelicans (2014–2017): In 2014, Aşık signed a long-term contract with the New Orleans Pelicans. During his four seasons with the team, he played a key defensive role. In the 2014–15 season, he averaged 9.8 rebounds per game.
• National Team: With the Türkiye U20 National Team, he won a silver medal at the 2006 European Championship. At the senior level, he represented Türkiye in the 2009 EuroBasket and the 2010 FIBA World Championship.

• 2007–08 Turkish Basketball League Champion (Fenerbahçe Ülker)
• 2006 European U20 Championship – Silver Medal
• Türkiye Basketball League All-Star (2007, 2008)
• 2010 FIBA World Championship – Silver Medal (was part of the preliminary squad)

Throughout his NBA career, Ömer Aşık was known for his defense and rebounding. Though not a high scorer, he was an efficient and impactful big man with strong shot-blocking ability, box-out technique, and a physical playing style. Due to chronic health issues and injuries, his professional playing career came to an end in 2018. His last NBA contract was terminated by the New Orleans Pelicans.