Brosnan is the only child of Thomas Brosnan, a carpenter, and May (née Smith, born circa 1934). He lives in Navan, County Meath for twelve years and considers it his hometown. He goes to Primary School in St. Annes Primary School, Navan. Brosnan’s father abandons the family when he is an infant. When he is four years old, his mother moves to London to work as a nurse. From that point on, he is largely raised by his grandparents, Philip and Kathleen Smith. After their deaths, he lives with an aunt and then an uncle, but is subsequently sent to live in a boarding house. He is educated at Elliott School, now known as Ark Putney Academy, a coeducational secondary school with academy status in southwest London.
Brosnan, after leaving comprehensive school at age sixteen, begins training in commercial illustration. He then goes on to train at Drama Centre London for three years. Following a stage acting career he rises to popularity in the television series Remington Steele (1982–87), which blends the genres of romantic comedy, drama, and detective procedural. After the conclusion of Remington Steele, Brosnan appears in films such as the Cold War spy film The Fourth Protocol (1987) and the comedy Mrs. Doubtfire (1993).
In 1994, Brosnan becomes the fifth actor to portray secret agent James Bond in the Eon Productions film series, starring in four films, GoldenEye, Tomorrow Never Dies, The World Is Not Enough and Die Another Day, from 1995 to 2002. He lends his likeness for Bond in the video games James Bond 007: Nightfire and James Bond 007: Everything or Nothing, providing his voice for the latter. During this period, he also takes the lead in other films including the epic disaster adventure film Dante’s Peak (1997) and the remake of the heist film The Thomas Crown Affair (1999). Since leaving the role of Bond, he has starred in such films as the musical/romantic comedy Mamma Mia! (2008), the Roman Polanski-directed political thriller The Ghost Writer (2010) and the action spy thriller The November Man (2014).
In 1996, along with Beau St. Clair, Brosnan forms Irish DreamTime, a Los Angeles-based production company. In later years, he has become known for his charitable work and environmental activism. He is married to Australian actress Cassandra Harris from 1980 until her death in 1991. He marries American journalist and author Keely Shaye Smith in 2001, and becomes an American citizen in 2004, holding dual citizenship in the United States and Ireland. He has earned two Golden Globe Award nominations, first for the television miniseries Nancy Astor (1982) and next for the dark comedy film The Matador (2005).