He sold more than 100 million records in France alone, scoring more than 200 hit singles (including 33 Number Ones). An icon in the French-speaking world since the very beginning of his career, some consider him to be the French equivalent of Elvis Presley. Today Hallyday is still considered as France's number-one singer and is seen as an unbelievable stage performer, giving incredible shows in crowded stadiums. Yet Hallyday remains largely unknown outside of France and the other French-speaking countries.

Johnny Hallyday was born Jean-Philippe Smet in Cité Malesherbes, Paris, France, to a French mother Huguette and a Belgian father Leon Smet. His parents separated not long after his birth, so he was raised by his paternal aunt, Hélène Mar. (His pseudonym was borrowed from his cousin's friend, Lee Halliday). In January 2006, he started a procedure to receive Belgian citizenship. His request is now being reviewed by Belgium's naturalisation commission.

Influenced by Elvis Presley and the 1950's rock revolution, Johnny, as he is popularly known, became famous in the 1960s from singing rock'n'roll in French. He appeared on the Ed Sullivan Show on July 1, 1962 with American singing star Connie Francis in a show that was taped at the famous Moulin Rouge nightclub in Paris. Since then, he has had a 40-year career in the music industry and is one of France's biggest stars. He has made 400 tours, had 18 platinum albums and performed in front of 15 million people.

He was married on April 12, 1965 to Sylvie Vartan (French singer) in Loconville. They have a son, David Hallyday (who is also a singer), born David Michael Benjamin Smet on August 14, 1966.Johnny was seen as a less caring father as his career had taken control of his life, his focus was more on his career and his next song rather than that of his family. Johnny Hallyday and Sylvie Vartan were France's "Golden Couple" of their generation. They divorced on November 4, 1980.

A year later, he married a model named Babeth Etienne on December 1, 1981 in Los Angeles, the marriage lasted 2 months and 2 days.

His love affair with the French actress Nathalie Baye began in 1982, after they met on a television programme. Nathalie gave birth to their daughter, Laura, at the end of 1983. They separated in 1986.

He married Adeline Blondiau in 1990. They divorced in 1992.

In 1996 he married Laetitia Boudou. In 2004 the couple adopted a Vietnamese baby girl, called Jade.