Patterson-Sewell moved with his parents to Australia when he was six years old and grew up in Gatton, Queensland, and began his youth career in Australia with the Toowoomba Raiders junior soccer system. While at the club he was regarded as one of the nation's most promising junior talents. He attended the Queensland Academy of Sport, and played junior football for a variety of youth clubs, but it was his play with the Toowoomba Raiders that helped him draw the interest of numerous European clubs. In 2004 Patterson-Sewell joined Anderlecht's reserve side. In late 2004 he was signed by Sheffield Wednesday's youth academy. Patterson-Sewell's spectacular play in goal at Sheffield Wednesday did not go unnoticed by bigger clubs. He was offered a chance to join Liverpool's Under 19 side and spurned Wednesday's contract offers. He appeared in 4 matches for the Liverpool Under 19 side in 2005.
Club career
In 2005–06, Patterson-Sewell returned to Australia once his work permit ran out to sign a temporary contract with Toowoomba Raiders and Mt. Gravatt in the Brisbane Premier League. He was expected to return to Belgium and play for a Liverpool feeder club.
In 2007, Patterson-Sewell signed with American USL Second Division side Cleveland City Stars instead of returning to Europe in hopes of impressing Major League Soccer clubs. While with Cleveland City, Patterson-Sewell helped the club to its first ever qualification to the US Open Cup in 2007. In eight appearances he had a goals against average of 1.00, including three shut-outs.
In early 2008, Patterson-Sewell went on trial with Major League Soccer club New York Red Bulls. His play in goal impressed New York Red Bulls and he was signed by the club in the 2008 MLS season. Paterson-Sewell made no appearances for Red Bulls and declined a contract offer to remain with club before the start of the 2009 MLS season. At the end of the 2009 season, Patterson-Sewell returned to the New York Red Bulls as the backup goalkeeper. Patterson-Sewell played in all of the preseason games for New York, including the final of the Walt Disney World preseason tournament in Florida, which New York won.
In February 2009, Patterson-Sewell was signed by Carolina RailHawks of the USL First Division for the USL 1 2009 season. At the end of the 2009–2010 season, New York was granted permission by MLS to sign Patterson-Sewell again on loan due to an "extreme hardship" case.
Patterson-Sewell remained at Carolina RailHawks for only a few months as he was transferred to Portugal in the 2011–2012 season transfer window to newly promoted Liga de Honra club Atlético Clube de Portugal for the 2011–2012 Liga de Honra season. Upon his arrival in Portugal he quickly established himself as Atlético's starting goalkeeper and was nominated for 2012 Goalkeeper of the Year award at the 2012 LPFP Awards.
Vitória de Setúbal
On July 1, 2012, Patterson-Sewell signed with Vitória Setúbal in the Primeira Liga for two years. At the end of the 2012 season Patterson-Sewell asked to be released from his contract.
Gil Vicente
On June 6, 2013, Patterson-Sewell signed with Gil Vicente FC in the Primeira Liga for two seasons following his former Atlético Clube de Portugal manager Joao de Deus.
Patterson-Sewell returned to the United States by signing a contract with NASL expansion side Rayo OKC on January 26, 2016. After a few months Caleb asked for a release from his contract allowing him to return to Portugal with SC Farense.
Farense
Patterson-Sewell signed with SC Farense in August 2016, playing 16 games for them, and leading them to a promotion place with one of the best goals against records in the country.
Jacksonville Armada
In February 2017, Patterson-Sewell signed with Jacksonville Armada FC of the North American Soccer League. Patterson-Sewell would finish the 2017 in the top three of all goalkeeper categories. He also broke the Jacksonville Armada FC clean sheet record.
In February 2018, Patterson-Sewell signed with defending MLS champions Toronto FC after Toronto acquired his MLS rights from New York Red Bulls in exchange for a fourth-round pick in the 2019 MLS SuperDraft. As the third-choice keeper for the first team, he has spent much of his time playing for the second team, Toronto FC II.
International career
Patterson-Sewell is an American Australian and is eligible to represent the Australia national association football team. The goalkeeper coach for Australia, Tony Franken, flew to Portugal to watch Patterson-Sewell play. Local media reports suggested Patterson-Sewell would be called up for Australia for their friendly against Romania.
