Sunny Deol is married to Lynda Deol (a.k.a. Pooja Deol), who comes from an Anglo-Indian family. Her father, Krishan Dev Mahal, is an Indian while her mother, June Sarah Mahal, is British. The couple has two sons, Karan (b. 1990) and Rajveer (b. 1994).

Lynda has also written the story of one of Sunny’s hit films - Yamla Pagla Deewana 2, while their son, Karan, was an assistant director on the same film and has rapped in a song sung by Diljit Dosanjh in the film. He made his Bollywood debut in 2019 with the Hindi-language feature film Pal Pal Dil Ke Paas, directed by Sunny. He then starred in the 2021 crime comedy film Velle, a remake of the Telugu film film Brochevarevarura. He is set to play a role in Sunny Deol's upcoming film Lahore 1947.

Deol is frequently recognised as a superstar of Indian cinema. He established himself as an action hero, with his roles in Arjun (1985), Ghayal (1990), Ghatak (1996), Border (1997), and Gadar: Ek Prem Katha (2001). Deol's portrayals personified masculinity and anti-authoritarianism in India. At the peak of his career, Deol was known for his muscular physique. He has been noted as one of the pioneers who kickstarted the trend of bodybuilding in Bollywood. Deol was one of the prominent actors of Hindi cinema in the 1980s, 1990s, and early 2000s, appearing in Box Office India's list of top actors nine times from 1989 to 2002. Deol topped the list twice, in 1997 and 2001. Deol was one of the highest paid actors of Hindi cinema during the 1990s. Since 1990, Deol has the third most bumper openings at the box office with a total of 10, behind only Shah Rukh Khan (18) and Salman Khan (14). He has also given three record openers since 1990 including Kshatriya (1993), Border (1997), and Indian (2001). Deol is the first and only Indian actor to deliver an all-time blockbuster as a lead hero after turning 60, he was 66 when he accomplished this landmark with his 2023 release Gadar 2. He has been compared to Sylvester Stallone, earning him the moniker of "Indian Rambo".

Many of Deol's films share unique elements which have become characteristic of his body of work. Primarily, his films often center around protagonists hailing from modest backgrounds, who find themselves entangled in conflicts with crime syndicates and systemic corruption. Despite seeking help from legal channels, the characters invariably encounter hurdles within the justice system, compelling them to take matters into their own hands and resort to vigilantism as a means of seeking retribution against the antagonists. This narrative framework serves as a vehicle for exploring broader societal issues, including the shortcomings of law enforcement, discrimination, exploitation of the marginalised, and pervasive corruption, which are portrayed through the protagonists' struggles and impassioned dialogues delivered by Deol.

In contrast to the stereotype of the silent action hero, Deol's characters are men of action and articulate numerous words. Initially conflict-avoidant, they pivot to unfiltered anger when met with opposition, progressing to threats of violence charged with indignation, and ultimately resorting to physical force. Notably, Deol's characters seldom instigate violence independently and only respond when provoked.

Deol is commonly addressed as "Sunny Paaji", signifying the term 'elder brother'. Deol is known for being a humble, shy, and gentle person, who values his privacy and does not socialize much. He is also seen as a passionate, loyal, and dedicated actor, who works hard and does not compromise on his beliefs. His father characterised him as "painfully introverted" and lamented that he remains very distant despite his capacity for love. Deol is often absent from industry parties and events. In an interview with NDTV, he explained that, early in his career, he was labelled as "snooty and snobbish". However, as people got to know him, they realised that his aloofness was simply due to shyness. Over time, invitations dwindled because people understood that he was unlikely to attend. He is also particularly known for his extreme shyness around his female co-stars.