Merchant was born into an Ismaili (Aga Khani) family in Mumbai to Siraj Merchant and Rizwana Merchant. She started her career in 1997 with the TV show Shaktimaan, in which she played Julia, an assistant. She then played Nonie in the popular show Hip Hip Hurray from 1998 to 2000. Kishwar then appeared in many successful popular shows like Babul Ki Duwayen Leti Jaa, Des Mein Niklla Hoga Chand, Kutumb, Kasautii Zindagii Kay, Kayaamat, Hatim and Khichdi.

Kishwar appeared in many Balaji shows like Kkavyanjali and Kasamh Se. In 2007, she played the positive role of Tamanna in Sanaya Irani and Arjun Bijlani’s popular youth show Miley Jab Hum Tum in 2008. She is very popular for playing Haseena in the popular Sukirti Kandpal and Vivian Dsena series Pyaar Kii Ye Ek Kahaani. She also played a role of Sonia in the second season of the hit show – Chhoti Bahu.

In 2010, Kishwer Merchant started dating co-actor Suyyash Rai. They got married on 16 December 2016.

In 2012, Merchant was seen in two shows Amrit Manthan and Arjun. Then came many shows like Hongey Judaa Na Hum and Parvarrish. She appeared in the popular shows Ek Hasina Thi as Raima, Madhubala – Ek Ishq Ek Junoon as Ananya, Kaisi Yeh Yaariyan as Nyonika and Itna Karo Na Mujhe Pyaar as Dimpy, sharing the screen with many popular actresses like Drashti Dhami and Sanjeeda Sheikh.

Merchant was a participant in the reality TV show Bigg Boss 9 along with her boyfriend Suyyash Rai in 2015. She was paired with Aman Yatan Verma. Merchant, was forced to quit the Ticket to Finale task in its last leg and walked out of the house involuntarily with Rs 15 lakhs.

In 2016, Kishwar made her comeback with Balaji’s popular show Brahmarakshas, playing the main antagonist- Aprajita.

In April 2017, Kishwar was seen in yet another Ekta Kapoor’s show, Dhhai Kilo Prem, which airs on Star Plus. She played a cameo appearance as Shilpa. In May 2017, she was seen in Rashmi Sharma’s Savitri Devi College & Hospital on Colors, but later she quit the show. Kishwar was also playing Asha in &TV’s show Gangaa, which stars Aditi Sharma. The show went off air on 2 June 2017.