Gregory Alexander, also known by the nickname "Brandy", is an Australian former professional rugby league footballer who played in the 1980s and 1990s, who has since become a radio, television commentator and rugby league journalist. During his playing career, Alexander played primarily as a goal-kicking halfback for the Penrith Panthers and the Auckland Warriors. He also played as a fullback, particularly in representative matches for New South Wales and Australia. Alexander was the captain of Penrith's 1991 NSWRL Grand Final winning team.

Alexander began his career at a schoolboy level where he quickly established himself as a star player for his side. He attended St Dominic's College, Penrith until year 11 (1981) then went on to play for the Australian Schoolboys rugby league team in 1983. He was later signed on as a junior to his local club side the Penrith Panthers. Alexander made his first-grade debut for the Panthers in the 1984 season as a half-back.

His talent quickly became clear and by the end of the season he took out the Rookie of the Year award. The following year Greg continued his good form throughout the season tallying up 194 points (a club record at the time) and earning himself the 1985 Dally M. player of the year award. Greg continued playing with the Panthers for the next several years and become known for his unique ability to score and set up tries, his excellent attacking kicking and his solid defence.

At the end of the 1986 NSWRL season, he went on the 1986 Kangaroo tour, gaining selection after Parramatta winger Eric Grothe was controversially ruled out with a knee injury. Alexander would go on to play in 10 matches on tour with the Kangaroos, scoring 10 tries and kicking 5 goals. 1989 saw him rise to selection for New South Wales in the 1989 State of Origin series, being one of the few Blues players regarded as playing well in a series won 3-0 by Queensland, before being selected as the first choice halfback for Australia's mid-season tour of New Zealand.

During the 1989 NSWRL season, his pace and skill had made Penrith the second most dangerous attacking team in the competition behind the eventual premiers, the Canberra Raiders and Alexander was the Panthers leading try and point scorer and for much of the year led the league in try-scoring – scoring ten tries in eight games at one point, eventually finishing with 15 tries from 18 games for the season.

With Alexander in great form at both halfback and fullback for the Panthers, the club made it to their first ever Grand Final in 1990 against the defending premiers Canberra. The Panthers went down 18–14 to the Raiders and despite a solid performance, Alexander's goalkicking let him down on the day, only kicking one of his four attempts.

Alexander captained the Panthers to their maiden premiership in 1991, the Panthers reversing the result of the 1990 Grand Final with a 19–12 win over Canberra. From halfback, Alexander took control of the game in the 2nd half with his kicking game which included a 38-metre field goal to give Penrith a 13–12 lead following a Brad Izzard try under the posts which was converted by Alexander. Later a majestic sideline conversion of Royce Simmons' 2nd try of the game sealed the win for the Panthers. The Phil Gould coached Panthers never fell below 4th on the ladder for the season and never lost the competition lead after regaining it following Round 14 of the 22 round season.

On 21 June 1992, his younger brother and fellow Panthers teammate Ben Alexander was killed in a car accident. The tragic loss of the younger Alexander had an adverse effect on the close-knit Panthers club and the team's form dropped off in the second half of the year which saw them miss the finals. At the end of the 1994 season after playing in just 13 games for the Panthers, Alexander joined the Auckland Warriors ahead of their inaugural season in the league as a way of dealing with his grief over Ben's death.

He spent most of the first half of his first season for the Warriors at halfback and began to recapture some of his previous form. In the latter half of the season he moved between fullback, halfback and five-eighth due to the depth the Warriors had in the halves – with Gene Ngamu, Stacey Jones, Phil Blake and Frano Botica all spending some time at halfback or five-eighth. In his second season with the club, he was awarded the captaincy after Dean Bell retired, and again began the season at halfback.

Alexander eventually returned to Penrith in 1997 after his stint in New Zealand and stayed on until his retirement in 1999. In total, Alexander played 228 games for the Panthers, scored 100 tries, kicked 343 goals and 14 field goals, tallying 1,100 career points for the club. To date, he is one of only seven players ever score over 100 tries and over 1,000 points for a single club in top grade Australian rugby league. The others being Terry Lamb (Canterbury-Bankstown), Ryan Girdler (Penrith Panthers), Hazem El Masri (Canterbury-Bankstown Bulldogs), Darren Lockyer (Brisbane Broncos), Luke Burt (Parramatta Eels) and Jarrod Croker (Canberra Raiders).

After his retirement from football in 1999, Alexander embarked on a media career in both radio and television. He currently works as a host for Foxtel's Fox Sports station. On 24 October 2000, he was awarded the Australian Sports Medal for his rugby league achievements. On 25 June 2016, he was inducted into the Penrith Panthers hall of fame alongside Grahame Moran, Royce Simmons, and Craig Gower.