Hall made his AFL debut for St Kilda in 1996. He helped fill the void of the record-breaking forward Tony Lockett, who had moved to the Swans the previous season. His most memorable performance for the Saints was his 3-goal burst during a five-minute period in the second quarter of the 1997 Grand Final, in which put his side in a strong position going into half-time, despite St Kilda going on to be defeated by Adelaide by 31 points at the MCG. He played for St Kilda until 2001, kicking 144 goals in 88 games and being the club’s leading goalkicker in the 1999 and 2001 seasons. He kicked a career-best 8 goals in Round 16, 2001 against the Western Bulldogs. He left St Kilda at the end of 2001 in style, kicking a goal after the final siren of a Round 22 match against Hawthorn to win the match. One of the main reasons for leaving was the rise of Nick Riewoldt, Justin Koschitzke and the recruitment of Fraser Gehrig, as well as salary cap constraints. Ironically, he left the year before Brian Waldron was appointed the club’s CEO.

Whilst playing in a reserves game for St Kilda against North Melbourne in Round 14 in 1997, Hall struck Sam McFarlane, a slightly built wingman, in the jaw, breaking it in three places. McFarlane spent the next three days in hospital getting the jaw wired back together and was sidelined for ten weeks. Although McFarlane returned for the final two games of the year, he never returned to play league football again.

In the 1998 second semi-final St Kilda held the lead over Melbourne near the end of the second quarter. After being tackled by Steven Febey, Hall dropped his knees into Febey’s head and after regaining his feet he slung Adem Yze to the ground. In frustration his outburst lead to an altercation with teammates Matthew Lappin and Shane Wakelin where Hall had to be restrained by his teammates and trainers. The incident resulted in a four-match suspension and Melbourne then took control of the match and won easily, ending St Kilda’s 1998 season.

In July 2002, while playing for Sydney, Hall was suspended for five matches after being found guilty of clawing the face of Port Adelaide ruckman Matthew Primus during a Swans loss at the SCG. Hall had been charged on video evidence with making “unreasonable and unnecessary contact to the face”. Hall acknowledged he had made contact with Primus’s face, but denied he had tried to eye-gouge him. “I made face contact which I regret, but it certainly looks worse than what it was” said Hall.

Hall earned a reputation as a controversial player, with several appearances at the tribunal resulting in four suspensions for a total of 10 matches. He has given away almost twice as many free kicks as he has been given over his career, and in 2003 Swans coach Paul Roos questioned whether Hall was given all the free kicks he deserved. Hall struggled with injuries through the 2007 season and his form was generally considered to be somewhat down from his peak, although he played a number of outstanding games and still led the club’s goalkicking with 44. In 2008, Hall began the season in good form but, following a punch thrown against West Coast Eagles player Brent Staker and a further incident where he aimed a punch at a Collingwood player, he missed a number of games and was suspended from the Swans’ team on 8 July 2008.

Hall joined the Swans for the 2002 season and prospered under the coaching of Paul Roos. He led the club’s goalscoring in every season up until 2009 and was named club Best and Fairest in 2004. He has said that he benefited from the move to Sydney, in particular the relative anonymity he enjoyed when first arriving, playing alongside Tony Lockett in Lockett’s comeback-from-retirement season. Hall’s form reached a high in 2004 when he was named in the All-Australian team. He then took his game to a whole new level from 2005, and not only bagged 80 goals for the season and a second placing for the Coleman Medal, but set up many more goals as well. He was selected in the All-Australian list in 2005 and 2006 and captained the Swans to their historic 2005 Grand Final premiership victory, their first since 1933. He led the Swans goalkicking in seasons 2005 to 2006, and in that two-year period he kicked two bags of seven against Essendon in their matches in Melbourne (a win in 2005 but a loss in 2006). He also led the club’s goalkicking in seasons 2007 and 2008, but in those two seasons he struggled with suspension and injury. He has also kicked big bags of goals against notably weaker opponents such as Carlton.

After an incident involving a punch to the stomach of St Kilda’s Matt Maguire in a 2005 preliminary final match, Hall was reported for a level two striking and offered a one-week suspension for a guilty plea. This suspension would have meant missing the next week’s grand final. Hall’s representation successfully argued that the incident was ‘in play’ despite the ball being 50 metres away. As a result, the charge was reduced to a level one offence which reduced the penalty to a reprimand and he went on to captain the Swans to their first premiership in 72 years, defeating the West Coast Eagles in the grand final by four points.

In Round 19, 2008, against the Fremantle Football Club, he kicked the last goal in the final minute and won the game by four points. He kicked a bag of goals in that game and in Round 20, against the Geelong Cats, he kicked five goals and one behind. In spite of the Swans’ 39-point defeat to the reigning premiers he was the leading goalkicker for the game. In 2008 Hall was awarded the Paul Roos Award for the best player in the finals. He finished the year as Sydney’s leading goalkicker for the seventh consecutive year, equalling the club record of Len Mortimer.

In 2008 Hall appeared in a series of “Barry Hall Hall” ads; however, these were pulled from the air following the Brent Staker incident.

Hall kicked his 600th career goal against the Western Bulldogs in Round 10, 2009, when he kicked six in that game. After a striking incident involving Adelaide’s Ben Rutten in his 250th game, Hall was put under an immense amount of pressure from coach Paul Roos to leave the club. Hall called a press conference on 7 July 2009 to announce that he was no longer going to play for the Swans. He kicked four goals in his last game for the club.

It was announced on 6 October 2009 that the Western Bulldogs had agreed to trade draft pick 47 for Hall with Sydney. On his Bulldogs’ debut, in the second round of the 2010 NAB Cup, he kicked six goals against Hawthorn. He then kicked four goals against Port Adelaide and had a part in the final and winning goal which gave the Bulldogs a place in the NAB Cup grand final against his first club, St Kilda. In the final he kicked seven goals, including five in the last quarter, to lead the Bulldogs to their first grand final success of any kind since 1970. He was awarded the Michael Tuck Medal for best on ground. He made his home-and-away debut for the Bulldogs in Round 1 against Collingwood at Docklands Stadium, but his side were defeated by 36 points. Hall kicked three goals.

Hall’s good form at the Bulldogs continued, with four and five goals in successive games helping him get back to his best form of his early years at the Sydney Swans. In 2010 Hall was tripped by Essendon defender and rival Dustin Fletcher in Round 10, costing Fletcher a one-match suspension. In Round 15 in 2010, he kicked six goals against Carlton and also suffered an ankle injury. He finished second on the 2010 Coleman Medal table with 73 goals in the home and away season, behind Richmond’s Jack Riewoldt. He kicked his 700th goal against the Gold Coast Suns in Round 3, 2011 and in Round 17, 2011 against North Melbourne he became the first player to kick over 100 goals for three clubs when he kicked five goals.

On 22 May 2010 Hall was again the centre of attention when he was pushed over by North Melbourne defender Scott Thompson while tying his shoelace, triggering an ugly altercation between Hall and several other North Melbourne players. Hall reacted to the taunts by putting Thompson in a headlock and was subsequently reported for both wrestling and rough conduct. He was later found guilty of wrestling and fined, but not guilty of rough conduct.

On 19 July 2011, Hall announced his intention to retire at the end of the 2011 season. Despite captaining Sydney to their 2005 premiership, Hall stated that he wanted to be remembered as a Bulldogs player due to them giving him a last chance at playing AFL football in 2010.

Barry Hall married Sophie Raadschelder after dating for about a year in November 2011. They separated in early 2015.

In 2015, Hall appeared in the Australian version of I’m a Celebrity…Get Me Out of Here!. Another contestant on that show was Lauren Brant with whom he developed a relationship. In May 2017 Brant and Hall announced the birth of their son, Miller Hall.

In 2018, Hall was immediately dismissed from radio station Triple M after making on-air remarks which were deemed unacceptable and inappropriate by station management.