Gauri Lankesh was born in a Kannada Lingayat family on 29 January 1962. Her Father is the poet-journalist P. Lankesh, who established the Kannada-language weekly tabloid Lankesh Patrike. She had two siblings, Kavitha and Indrajit.

Gauri started her career as a Journalist with The Times of India in Bangalore. Later, she moved to Delhi with her husband, Chidanand Rajghatta. Shortly after, she returned to Bangalore, where she worked as a correspondent for the Sunday magazine for nine years. At the time of her father's death in 2000, she was working for the Eenadu's Telugu television channel in Delhi. By this time, she had spent 16 years of her life as a Journalist.

Beginning in 2001, differences developed between Gauri and Indrajit over the paper's ideology. These differences became public in February 2005, when a report about a Naxalite attack on policemen, approved by Gauri, was published in the magazine. On 13 February, Indrajit (who was the paper's proprietor and publisher) withdrew the report, alleging that it favored the Naxals. On 14 February, Indrajit filed a police complaint against Gauri, accusing her of stealing a computer, printer, and scanner from the publication's office. Gauri filed a counter-complaint, accusing Indrajit of threatening her with a revolver. On 15 February, Indrajit held a press conference, where he accused Gauri of promoting Naxalism through the paper. Gauri held a separate press conference where she denied the accusation and stated that her brother was opposed to her social activism. Gauri subsequently started her own Kannada weekly called Gauri Lankesh Patrike.

Gauri was a staunch critic of right-wing Hindutva politics. In 2003, she opposed the Sangh Parivar's alleged attempts to Hinduise the Sufi shrine Guru Dattatreya Baba Budan Dargah located at Baba Budan giri. In 2012, while participating in a protest demanding a ban on communal groups in Mangalore, she stated that Hinduism was not a religion but a "system of hierarchy in society" in which "women are treated as second-class creatures". She endorsed a minority religion tag for the Lingayat community and headed the Komu Souharda Vedike, a communal harmony platform for the oppressed communities. She was also of the view that the followers of Philosopher Basavanna were not Hindus.

On 23 January 2008, Gauri published an article titled "Darodegilada BJP galu" in her tabloid. The article criticised the BJP Leaders Pralhad Joshi, Umesh Dushi, Shivanand Bhat, and Venkatesh Mestry. The article stated that the three BJP workers had cheated a jeweller of ₹100,000. It also stated that the jeweller sought justice from Member of Parliament Joshi and threatened to approach the police should Joshi refuse to help him. Gauri later said that the article was based on "sources within the BJP".

Gauri was known for advocating freedom of the press. She had written about the wrongdoings of the Indian National Congress leader, D. K. Shiva Kumar, a close associate of the former Chief Minister of Karnataka, S. M. Krishna. She was opposed to the Bharatiya Janata Party (BJP) and ended her 35-year old friendship with Prakash Belawadi when the latter became a media advisor to the BJP during the Indian general election, 2014. In November 2014, the Congress-led Karnataka government appointed Gauri as a member of a committee aimed at convincing the Naxalites to give up violence and surrender. However, a delegation of BJP Leaders accused her of being a Naxalite sympathiser and demanded her removal from the committee. The chief minister Siddaramaiah rejected the demand.

Gauri was openly critical of the caste system. In 2015, some Brahmins accused her of criticising the Novelist S. L. Bhyrappa and Brahminism during the 81st Kannada Sahitya Sammelana (Kannada literary conference) held at Shravanabelagola. At the conference, Gauri remarked that the low-caste author Perumal Murugan was criticised by right-wing Hindu groups for depicting a childless Hindu couple who indulged in consensual sex rituals outside of marriage in order to have children. She then pointed out that the Brahmin Novelist S. L. Bhyrappa had also depicted the similar Niyoga practice in his novel Parva, a retelling of the Hindu epic Mahabharata. She clarified that she was supportive of both these Writers, and asked why the Hindu groups who were offended by Perumal Murugan were not offended by Bhyrappa. On 19 February 2015, protesters from the Hassan Zilla Brahmin Sabha ("Hassan district Brahmin Association") organised a rally against her, urging the police to register a First Information Report against her.

On 27 November 2016, the second JMFC court concluded that Gauri had failed to provide any substantial evidence for her criticism of the BJP Leaders and found her guilty of defamation. The court imposed a fine of ₹5,000 on her in each case. Besides the total fine of ₹10,000, the court also sentenced her to six months imprisonment. Her co-accused, Dev Anand Jagapur, was acquitted by the same court. The same court granted her anticipatory bail, however, which made her avoid prison time.

On 5 September 2017, three unidentified men shot Gauri to death at her house in Rajarajeshwari Nagar, Bangalore. The men fired at least seven bullets at her at around 8 p.m. while she was unlocking the main door of her house after returning from her office. One of the killers, who was waiting for her near her house, fired the first shots at her, while the two others, who are suspected to have followed her from her office, joined the initial shooter thereafter. The killers were wearing helmets and escaped on a two-wheeler Honda Dio after the murder. Three of the bullets pierced Gauri's head, neck, and chest, resulting in her death at the scene.