Marlenny Deenerwan holds a PhD in Theatre Performance from Monash University, Australia (2016), a Master of Arts (2011) and a Bachelor of Performing Arts in Drama (2007) from Universiti Malaya and a Diploma in Creative Writing from the National Arts Academy, now known as ASWARA (2002). 

Before entering the academic world, she was a teacher at SM Shan Tao in Kota Kinabalu, Sabah, and worked as a sub-editor at Daily Express Sabah. As an academic, her research is in the field of Malaysian traditional and ritual theatre: Bobolian rituals in Sabah, the traditional theatre of Wayang Kulit, Makyong and Bangsawan, research on the Minang community in Kuala Lumpur and the Kaul event of the Melanau community in Mukah. Her most recent research focused on the development of interactive theatre as an alternative to teaching and learning in primary school. This project started in 2017 in a rural school in SK Pekan Ranau, Sabah under the UMRG grant and was further developed into a DraFDidik module. This is a teaching and learning method using drama/theatre for passive children that was tested in five primary schools in the Klang Valley in 2023, funded by a UMCares grant. In November 2023, Marlenny won Silver Award in International Education Innovation Expo 2023 through the project DraFDidik.

Marlenny has been a creative writer since 1999 and has published over 20 scripts for modern stage dramas and adaptations (Nur, Dari M ke M, Rumah Lama Kampung Baru, Melati & Melur, YB Jee, Lina & Lijah, No Smoking Please, Lima Bersaudara, Anak Raja Anak Papa, Zhao Si Anak Yatim, Hikayat Si Miskin Menjadi Raja, Elyas Emas, Perempuan-Perempuan Kampong Bharu, Transit Borneo-Malaya etc.), dozens of TV dramas since 2003 (Haryati II, Dilema Wanita, Kasihnya Di Bawah Bayu, Igauan Semalam, etc.). She also writes documentaries, television commercials, newspaper articles/critiques, short stories, poems, and song lyrics. She has worked as an actress, director, and theatre producer since 1998.

Her directing credits include No Smoking Please (2003), The Glass Menageries (2006), Rachel Corrie (2007), Di Sebalik Pintu (2008), Melati & Melur (2008), The Zoo Story (2009), Rumah Lama Kampung Baru (2010), Bangsawan Anak Raja Anak Papa (The Prince and The Pauper) (2015), Zhao Si Anak Yatim (2017 & 2018), Asiah Samiah (2019), Hikayat Si Miskin Menjadi Raja (2021), Bangku (2022), Saya... Dari Hujung Kota (2023), Transit Borneo-Malaya (2023), Wanita dan Senjatanya (2023), Perempuan-Perempuan Kampong Bharu (2024), Sirih Bertepuk Pinang Menari (2024), Tingginya Menyapu Awan (2025) and Muzikal Uda & Dara (2025). She co-founded the theater group Mekar Budaya in 2002 and the group Bangsawan Opera Sri Bandaraya under the patronage of Kuala Lumpur City Hall in 2008. She won the Best Actress Award at the Malaysian Theater Festival 2003, the Best Director Award at the Kuala Lumpur Theater Festival 2009, the Young Theater Artist Award by the Selangor State Government in 2010, and the Best Original Script Cameronian Boh Award 2025. Her Bangsawan script Lima Bersaudara was recorded in the Malaysia Book of Records as the first Bangsawan script for children in 2010. She was appointed by the National Ministry of Culture and Arts as the Head of Jury for the 2016 Malaysian Theater Festival. She was the Head of Jury for the Universiti Malaya (Kaviter UM) Theater Carnival from 2017 to 2024. 

Apart from being an author for the Sekolah Seni Malaysia textbooks, Marlenny has published several academic books, including "Bobolian Seni Teater Etnik Dusun" (2015, JKKN), "Siri Teater Muzikal" (2024, DBP), and her latest publication, "Seni Teater Bangsawan" published by DBP in 2025. During her stint with the NGOs, Marlenny was the former President of ASWARA Alumni Association 2015-2018 and is currently the Chairperson of Persatuan Rumpun Seni Mekar Budaya Kuala Lumpur (since 2020). She has also been a member of Ikatan Penulis Sabah since 1992. In December 2024, she received the Anugerah Khas Cendekia (Seni Teater) at Dewan Bahasa dan Pustaka Kuala Lumpur.