John Joseph “Jack” Nicholson was born in Neptune City, New Jersey on April 22, 1937.¹⁾

He is the son of June Frances Nicholson (November 5, 1918 – July 31, 1963), a showgirl (stage name June Nilson).²⁾

Nicholson's mother hailed from Ireland, England, and Germany.³⁾

In 1936, she married Italian-American showman Donald Furcillo (stage name Donald Rose) without knowing he was already married.⁴⁾

In his book Jack's Life, biographer Patrick McGilligan speculated that June's manager, Eddie King (formerly Edgar A. Kirschfeld), was Nicholson's real father rather than Furcillo.⁵⁾

When Nicholson was born, June was only 18 years old, unmarried, and unsure of his father's identity. Her parents decided to raise Nicholson as their own kid without exposing his actual paternity, and June would pose as his sister.⁶⁾

Time magazine researchers discovered and notified Nicholson in 1974 that his “sister”, June, was actually his mother, and his other “sister”, Lorraine, was actually his aunt.⁷⁾

His mother and grandmother had both deceased at this point (in 1963 and 1970).⁸⁾

Nicholson grew raised in the New Jersey town of Neptune City.⁹⁾

He was brought up in his mother's Roman Catholic faith.¹⁰⁾

His family relocated to an apartment in Spring Lake, New Jersey, before he started high school.¹¹⁾

“Nick,” as he was known to his high school pals, went to nearby Manasquan High School, where the Class of 1954 elected him “class clown”.¹²⁾

Nicholson attended his 50th high school reunion in 2004, escorted by his aunt Lorraine.¹³⁾

He served in the Air National Guard for a while.¹⁴⁾

Nicholson is well-known for a diverse spectrum of starring and supporting parts, including sarcastic humor, romance, and grim depictions of antiheroes and psychopathic characters.¹⁵⁾