She was born in Ankara on October 14, 1980. Her mother's origins are from Izmir, Istanbul and Thessaloniki, and her father's origins are from Bulgaria. She completed her primary and secondary education in Izmir. She became the 3rd beauty of the Miss Turkey competition organized by Kanal D in 2000 and started modeling professionally. She left the Department of Archaeology of Istanbul University Faculty of Letters and focused on modeling. She took part in fashion shows of fashion designers such as Hakan Yıldırım, Cengiz Abazoğlu, Ümit Ünal, Evrim Timur, Arzu Kaprol, Bahar Korçan and Dilek Hanif. Cansu Dere, who represented Türkiye in all of İTKİB's organizations abroad, participated in various fashion shows in Paris between 2002 and 2003 and worked with many important photographers.
Dere, who appeared in an Arçelik commercial in 1998, entered the television world in 2000. She had her first presenting experience with the Children and Music program on Kanal D. Then, in 2004, she presented the competition called Türkiye'nin Yıldızları broadcast on Show TV. In addition to presenting, she also worked as an editor in the Life Style Moda program broadcast on NTV. In 2005, she hosted the N Moda program again on NTV.

In 2004, she started her acting career with the series Metro Palas, directed by Hilal Saral and adapted from the American sitcom Sex and the City. Later, she played the character "Irmak Bozoğlu" in the series Alacakaranlık, directed by Türkan Derya. In 2005, Dere attracted attention with her role as "Ceylan" in the series Güz Yangını, directed by Zeynep Günay. During this period, she played the character of villager "Esma" in the movie Kabuslar Evi, which was shot in the TV movie format by Çağan Irmak. In 2006, she appeared in an Opet commercial with Cem Yılmaz and Zafer Önen. She increased her popularity by playing the leading role with Mehmet Akif Alakurt in the series Sıla, which was broadcast between 2006-2008. She started to gain fans with the series in which she appeared as the character "Sıla". In 2007, she starred alongside Kenan İmirzalıoğlu in the period film Son Osmanlı Yandım Ali, in which she played the character of "Defne", and it was watched by over 1 million viewers.[citation needed] In 2009, she starred in the film Acı Aşk, written by Onur Ünlü and directed by Taner Elhan. She played a photographer named "Oya" in the film, in which she shared the lead roles with Halit Ergenç, Songül Öden and Ezgi Asaroğlu.

She became even more famous with her role as "Eyşan" in the Ezel series, which left its mark on the period in 2009. Also in 2009, she voiced the characters of Alex and Mandy in the movie Totally Spies: How Did Everything Begin in Spy Girls?. In 2010, she played the character of "Mary Lou" in the movie Yahşi Batı.

In 2011, she shot her third movie, Behzat Ç. Seni Kalbime Buried, directed by Serdar Akar. In the movie, she played a police officer named "Songül". In 2012, she took on the leading role again in the movie El Yazısı. This time, Dere took on the role of "Zeynep", a pharmacist working in a small town.

She took part in the Magnificent Century series as the Iranian "Firuze" character. In October 2016, she played the character "Zeynep" in the series Anne, which started airing on Star TV. Later, in 2018, she played the character "Nevra Elmas" in the series Şahsiyet, which was broadcast on the internet platform puhutv, where she shared the lead role with Haluk Bilginer. In 2019, she played the character "Banu Karalı" in the series Ferhat ile Şirin, which was broadcast on FOX, where she shared the lead role with Tolga Sarıtaş, but the project did not last long and ended in its 6th episode. In 2020, she played the character "Asya Yılmaz" in the series A Woman Scorned, which is the Turkish adaptation of the British series Doctor Foster, which was broadcast on Kanal D, where she shared the lead role with Caner Cindoruk and Melis Sezen. The series ended with its 60th episode on May 25, 2022.