Born Randall Hank Earl Williams in Shreveport, Louisiana, his famous father bestowed upon him the nickname Bocephus (named after Grand Ole Opry comedian Rod Brasfield's ventriloquist dummy). He was raised by his mother Audrey after his father's death in 1953. While he was a child, a huge array of contemporary musicians visited him, influenced, and taught him various music instruments and styles. These influences include: Johnny Cash, Fats Domino, Earl Scruggs, Jerry Lee Lewis and many, many more. He began performing when he was eight years old, and in 1963, he made his recording debut with "Long Gone Lonesome Blues," one of many of his father's classic songs.

Although Williams's recordings earned him numerous country hits throughout the 1960s and early 1970s with his role as a "Hank Williams clone", he became disillusioned and decided to pursue his own musical direction and tastes. After recording the soundtrack to Your Cheatin' Heart a biography of his father, Williams, Jr. hit the charts with one of his own compositions, "Standing in the Shadows (Of a Very Famous Man)". The song signalled a move to rock and roll and other influences, as he tentatively began to step out of the titular shadow of his father.

Also during this time, Williams had his first two No. 1 songs: "All For the Love of Sunshine" (1970, featured on the soundtrack to Kelly's Heroes) and "Eleven Roses" (1972).

By the mid-1970s, Williams began to pursue musical direction that would, eventually, make him a superstar. While recording a series of moderately successful songs, Williams began to heavily abuse drugs and alcohol, and eventually attempted suicide in 1973. Upon moving to Alabama in an attempt to re-focus both his creative energy and his troubled personal life, Williams began playing music with Southern rock musicians Waylon Jennings, Toy Caldwell, Marshall Tucker Band and Charlie Daniels and others. Hank Williams Jr. and Friends, what is often called his "watershed" album, was the product of these then-groundbreaking collaborations.

Williams' career began to hit its peak after the Nashville establishment gradually – and somewhat reluctantly – accepted his new sound. His popularity had risen to such levels that he could no longer be overlooked for major industry awards. He was extremely prolific throughout the 1980s, sometimes recording and releasing two albums a year. Family Tradition, Whiskey Bent and Hell Bound, Habits Old and New, Rowdy, The Pressure is On, High Notes, Strong Stuff, Man of Steel, Major Moves, Five-0, Montana Cafe, and many others resulted in a long string of hits. In 1987 and 1988, Williams was named Entertainer Of The Year by the Country Music Association. In 1987, 1988, and 1989, he won the same award from the Academy of Country Music. The pinnacle album of his acceptance and popularity was Born to Boogie. During the 1980s, Williams became a country music superstar known for catchy anthems and hard-edged rock-influenced country.

His 1989 hit was "There's a Tear in My Beer," a duet with his father, that was created using electronic dubbing techniques. The song itself was written by his father, and was recorded with Hank Williams playing just his guitar. The music video for the song combined existing television footage of Hank Williams performing and the dubbing techniques transferred the image of Hank Jr. onto the screen, so it appeared as if he were actually playing with his father. The video was both a critical and commercial success. It was named Video Of The Year by both the Country Music Association and the Academy of Country music. Hank Williams, Jr. would go on to win a Grammy award in 1990 for Best Country Vocal Collaboration.

He is probably best known today as the performer of the theme song for Monday Night Football, based on his 1984 hit, "All My Rowdy Friends Are Coming Over Tonight". The opening theme became a classic, as much a part of the show as the football itself. In 1991, 1992, 1993, and 1994, Williams's opening themes for Monday Night Football would earn him four Emmy awards.

On December 26, 2005 Hank Williams, Jr opened for Monday Night Football on Abcfor the last time. In 2006, Monday Night Football moved to Disney corporate sibling, ESPN. Hank Williams, Jr. continues to open the show.

For MNF's 2006 debut on ESPN, Williams Jr. re-recorded the MNF opening theme with an all-star jam band that included Little Richard, Joe Perry, Clarence Clemons, Rick Nielsen, Bootsy Collins, Charlie Daniels, Steven Van Zandt and others.

On April 10, 2006, CMT honored Williams with the Johnny Cash Visionary Award, presenting it to him at the 2006 CMT Music Awards. Williams joins an elite circle of gifted performers to have received this prestigious mark of distinction, including Loretta Lynn (2005), Reba McEntire (2004), Johnny Cash (2003).