She is a distinguished Indian politician known for her impactful contributions to Bihar's political landscape. She rose to prominence as the 7th Deputy Chief Minister of Bihar, serving from 16 November 2020 to 9 August 2022, and made history by becoming the fifth female Deputy Chief Minister of India from Bihar in 2020. Hailing from the Noniya caste, classified as an Extremely Backward Class (EBC) community, Renu Devi grew up as the eldest among her siblings, showing early signs of leadership and determination. After completing her secondary education in 1977 from the Babasaheb Bhimrao Ambedkar Bihar University, she embarked on a journey that would intertwine her life with social activism and politics.

Renu Devi's entry into politics was influenced by her mother's association with the Sangh Parivar, a collective of Hindu nationalist organizations. She joined the BJP Mahila Morcha, the women's wing of the Bharatiya Janata Party, in 1988. Her dedication and leadership skills quickly became apparent, leading to her appointment as the head of the wing in the Champaran region in the following year.

Over the years, Renu Devi held several key positions within the BJP and the Bihar State Government. She served as the Minister of Sports, Arts, and Culture in the Bihar State Government from 2005 to 2009, where she demonstrated her commitment to promoting cultural and sporting activities. Additionally, she was a national vice-president of the BJP from 2014 to 2020.

Despite facing defeat in her first electoral contest in 1995 from the Nautan Assembly seat, she remained undeterred and went on to win four consecutive elections from Bettiah, another division of West Champaran district, to the Bihar Legislative Assembly (2000-2015; 2020–present). Her loss in the 2015 elections was followed by a remarkable comeback in 2020, highlighting her resilience and strong connection with the people of Bihar.

In 2020, Renu Devi reached a significant milestone in her career when she was appointed as the Deputy Chief Minister of Bihar, a decision that was met with widespread approval.