Andrew Roy Gibb (5 March 1958 – 10 March 1988) was an English singer and musician. He rose to international fame in the late 1970s as a teen idol and pop star. The younger brother of Barry, Robin, and Maurice Gibb of the Bee Gees, Gibb achieved major success in close collaboration with his brothers. He was the first solo artist to have his first three singles reach number one on the US Billboard Hot 100.

Born in England and raised in Australia, Gibb began performing professionally in his teens before moving to the United States, where he signed with RSO Records. His debut album, Flowing Rivers (1977), produced three US number-one singles: "I Just Want to Be Your Everything," "(Love Is) Thicker Than Water," and "Shadow Dancing," the last of which also topped charts internationally and became his signature song. His subsequent albums, Shadow Dancing (1978) and After Dark (1980), further cemented his popularity.

In the early 1980s, Gibb expanded into theater and television, starring in productions of The Pirates of Penzance (1981) and Joseph and the Amazing Technicolor Dreamcoat (1982), and co-hosting the music show Solid Gold (1981–82). However, his career was disrupted by substance abuse and depression, leading to declining commercial success. In 1988, just days after his 30th birthday, Gibb died from myocarditis, exacerbated by years of drug use.

Andy Gibb was born on 5 March 1958 at Stretford Memorial Hospital, Stretford, Lancashire. He was the youngest of the five children born to Barbara and Hugh Gibb. His mother was of English and Irish descent, and his father was of Scottish and English descent. He had four siblings: his sister, Lesley; and three brothers—Barry and fraternal twins Robin and Maurice.

At the age of six months, Gibb immigrated with his family to Queensland, Australia. The family shared three different homes at Redcliffe, Queensland, north of Brisbane, before settling on Cribb Island, a former suburb of Brisbane, in January 1960. After moving several times between Brisbane and Sydney, Gibb returned to the United Kingdom in January 1967 as his three older brothers began to gain international fame as the Bee Gees.

In his childhood, his mother, Barbara, described Gibb as "A little devil, a little monster. I'd send him off to school, but he'd sneak off to the stable and sleep with his two horses all day. He'd wander back home around lunchtime smelling of horse manure, yet he'd swear he had been at school. Oh, he was a little monkey!" Producer and film director Tom Kennedy described Gibb's personality in his childhood:

Andy was always around—he was this cheeky little lad, Hugh and Barbara doted on him, so he would have a limo to go around London with his pals and twenty quid to go to the cinema. It was unheard of in those days! But he was just a cheeky little lad with a heart of gold. He used to try to get me to buy him beer when he was underage—he would only have been about 11 or 12.

Gibb dropped out of school at the age of 13, and with an acoustic guitar given to him by his older brother Barry, he began playing at tourist clubs around Ibiza, Spain (when his parents moved there), and later on the Isle of Man, his brothers' birthplace, where his parents were living at the time.