Sampath Kumar (18 September 1950 – 30 December 2009), known by his stage name Vishnuvardhan, was an Indian actor who worked predominantly in Kannada cinema besides also having sporadically appeared in Tamil, Hindi, Telugu and Malayalam language films. Vishnuvardhan has a prolific career spanning over four decades, during which he has acted in more than 220 films. A popular cultural icon of Karnataka, and holds the status of a matinée idol among the Kannada diaspora. He is popularly called as Sahasa Simha, Dada and The Angry Young Man of Kannada Cinema. Vishnuvardhan's contributions to Kannada cinema have been praised by his contemporaries in the Indian film industry. The Government of Karnataka honoured him with the Rajyothsava Prashasthi in 1990 and the Dr. Rajkumar Lifetime Achievement Award in 2007 for his contributions to Kannada cinema. The Government has announced to confer him the state's highest civilian award, Karnataka Ratna, in September 2025. He was called The Phoenix of Indian Cinema. In 2008, a poll conducted by CNN-IBN listed Vishnuvardhan as the most popular star in the Kannada film industry.

Vishnuvardhan made his acting and on-screen debut at age 21 in B. V. Karanth and Girish Karnad's Vamsha Vriksha in 1971. In 1972, he attained stardom after starring in Puttanna Kanagal's Naagarahaavu . By the late-1970s, he established himself as a bankable leading actor after starring several successful films throughout the 70's; the crime drama Sahasa Simha released in 1982 catapulted him into superstardom in Karnataka. He predominantly works in Kannada films, but he has also appeared in some of Hindi, Tamil, Telugu and Malayalam films. Some of his best known non-Kannada films include the Tamil mythological Sri Raghavendrar (1985) and the Malayalam crime thriller Kauravar (1992). He was also the story writer of the 1997 film Ganesha I Love You directed by Phani Ramachandra.

Vishnuvardhan has won seven Filmfare Award South – six Best Actor and one Filmfare Lifetime Achievement Award – South, three Cinema Express Awards for Best Actor and eight Karnataka State Film Awards—seven Best Actor and one Dr. Rajkumar Lifetime Achievement Award. He has won the second most number of Best Actor awards at the Karnataka State Film Awards, behind Dr. Rajkumar. As an acknowledgment of his service to Indian cinema, the state government named its annual lifetime achievement award to long-serving film personalities after Vishnuvardhan, renaming it as the Karnataka State Dr. Vishnuvardhan Award. A road stretching 14.5 kilometres (9.0 miles) from Banashankari Temple to Kengeri in Bangalore was named after him. It is the longest road in India to be named after an actor.

Vishnuvardhan was born in Mysore to H. L. Narayana Rao and Kamakshamma. His father was an artist and music composer who was known for his collection of musical instruments and was also a screenwriter who had written dialogues for the 1961 Kannada movie Nagarjuna as well as story, screenplay, dialogues and lyrics for the 1962 Kannada movie Vidhivilasa. He had six siblings. His sister Rama was a Kathak dancer at the Mysore Palace, and brother Ravi was a child actor who appeared in the 1955 Tamil – Kannada bilingual film Modala Thedi. Vishnuvardhan was educated first in Mysore's Gopalswamy School and then at Bangalore's Kannada Model High School. He attended high school and obtained a degree from National College, Basavanagudi, Bangalore.

Vishnuvardhan married actress Bharathi on 27 February 1975 in Bangalore. They have two adopted daughters, Keerthi and Chandana. Actor Aniruddha Jatkar is married to Keerthi Vishnuvardhan.

Vishnuvardhan started his career with the National Award-winning movie Vamshavruksha (1971) directed by Girish Karnad based on the novel by S. L. Bhyrappa. His first lead role was in Naagarahaavu, directed by Puttanna Kanagal and based on a trilogy by T. R. Subba Rao. He won the Karnataka State Film Award for Best Actor for this film. Next, he appeared along with Rajkumar in Gandhada Gudi (1972). It got a stupendous reception at the box office. In 1974, he appeared in Bhootayyana Maga Ayyuwhich is considered an important milestone in the history of Kannada cinema. He appeared in many Kannada movies of which three were with Rajinikanth who was then a budding star – Sahodarara Savaal (1977), Galate Samsara (1977) and Kiladi Kittu (1978). He acted in the hit romantic drama Hombisilu (1978) and his role of a doctor fetched him his second Karnataka State Film Award for Best Actor. During the 70s, Vishnuvardhan formed a successful pair with not only his actress wife Bharathi, but also the two top actresses of the decade – Aarathi and Manjula. He was in Tamil films like Alaigal (1973) and Mazhalai Pattalam (1980).

He made his debut in Malayalam cinema in 1981 with Adima Changala.

In 1982, the Joe Simon directed Sahasa Simha became a blockbuster and bestowed the title of Sahasa Simha on him.