|Full name||Cássio José de Abreu Oliveira|
|Date of birth||8 January 1980|
|Place of birth||Rio de Janeiro, Brazil|
|Height||1.69 m (5 ft 7 in)|
|Playing position||Left back|
|Current club||Adelaide United|
|2002||→ Internacional (loan)||44||(1)|
|2003||→ Atlas (loan)||0||(0)|
|2005||New England Revolution||3||(0)|
|2005||→ Brasiliense (loan)||7||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 5 December 2013.
† Appearances (Goals).
Cássio began playing as a left back with local side Flamengo. After missing a penalty kick in the 2001 Copa Mercosur final, his career with Flamengo was effectively over and he was loaned to Internacional and Mexican Primera División side Atlas in 2002 and 2003. While at Internacional, Cássio won the 2002 Campeonato Gaúcho and scored the club's 1000th goal in Brazilian competitions. He played in Série B with Marília during the first half of 2004, before joining Primera División Paraguaya side Olimpia in July 2004. He had a brief spell with the New England Revolution, making only three appearances before being released mid-way through the 2005 season.
Cassio's arrival at Adelaide United came after all of the club's options at left-back (Matthew Kemp, Adam van Dommele and Aaron Goulding) were either released or transferred at the end of the 2006–07 A-League season. Although failing to score during his debut A-league campaign, his 3 assists, and contribution of 14 shots on target, revealed how dangerous Cassio was as an attacking force. For his significant contributions on the field for the 2007–08 season, he was given three end of season awards, including the Club Champion award.
Despite a slow start to the 2008–2009 A-League season due to injury, Cassio proved just how valuable he had become to the club when he set up all three of Adelaide United's goals against FC Bunyodkor in the first leg semi-final of the 2008 AFC Champions League. On 15 October 2008 Cassio signed a new 2 year deal with United despite interest from rival A-League clubs with the Brazilan stating that although they offered more money Adelaide was "like a second home" for the player.
Despite coming to Adelaide with a reputation of a goal scorer Cassio's first goal came midway through his second season with the club; a brilliant free kick against Melbourne Victory in late October. In December, Cassio scored a brace in Adelaide's 6–1 demolishing of Wellington with both goals coming from unstoppable drives after he cut in from the left channel.
On 3 January 2009, Cassio scored his 4th goal for Adelaide United against in the annual Sydney FC clash at Adelaide Oval. Adelaide went on to win the game 2–0. In the semi-final second leg against Melbourne Victory, Cassio was sent off by referee Matthew Breeze, and made a gesture toward the Melbourne crowd as he departed down the tunnel. In the 2009/10 season Cassio scored 2 stunning goals, one from a free kick against Perth Glory and goal of the season-contender against Newcastle Jets to level the match at 1–1.
On 12 September 2011, Cassio revealed a desire to become an Australian citizen and play for the Socceroos. Cassio and his family became Australian citizens at a ceremony at Hindmarsh Stadium on 7 September 2012. As a result, he does not require a visa to play for Adelaide United, thus enabling the club to import another player on visa.
On 21 November 2012 he signed a two year contract extension keeping him at the club until the end of 2014-15 A-League season.
(Correct as of 1 February 2011)
1 – includes A-League final series statistics
2 – includes FIFA Club World Cup statistics; AFC Champions League statistics are included in season commencing after group stages (i.e. 2008 ACL in 2008–09 A-League season etc.)
- Adelaide United Club Champion: 2007–08, 2010–11
- Adelaide United Player's Player of the Year: 2007–08
- "Flamengo cede Cássio al Atlas" (in Spanish). Crónica. 16 January 2003.
- "Flamengo empresta lateral Cássio ao Atlas, do México" (in Portuguese). Pense Carros. 16 January 2003.
- "Hoy llega lateral brasileño Cassio" (in Spanish). ABC Digital. 22 July 2004.
- "Revolution release midfielder Cassio". ESPN.com. June 28, 2005.
- "Adelaide recruit defender Cassio". Fox Sports. 6 June 2007. Retrieved 4 January 2009.
- "Cassio cleans up at Red Carpet Awards". Adelaide United. 6 March 2008. Retrieved 6 March 2008.
- Rossi, Hannibal (9 October 2008). "Adelaide United topple Zico’s men 3–0 in ACL semifinal". The Roar. Retrieved 4 January 2009.
- "Cassio commits to future with Adelaide United". Adelaide United. 15 October 2009. Retrieved 4 January 2009.
- Wilson, Marcus (31 October 2008). "Victory regains top spot". A-League. Retrieved 4 January 2009.
- Wilson, Marcus (5 December 2008). "Rampant Reds run riot". A-League. Retrieved 4 January 2009.
- "Adelaide United add to Sydney FC's misery with a 2–0 win at Adelaide Oval". Fox Sports. 3 January 2009. Retrieved 4 January 2009.
- "Melbourne Victory beat Adelaide United in A-League". 14 February 2009.[dead link]
- Micallef, Philip (12 September 2010). "Cassio's green and gold dream". theworldgame.sbs.com.au. Retrieved 7 July 2012.
- "Cassio inks new deal to stay in Adelaide". footballaustralia.com.au. Retrieved 21 November 2012.
- "Player Profile: 6. Cassio". Adelaide United. Retrieved 1 February 2011.
|Adelaide United Club Champion Award
|Adelaide United Club Champion Award