He began playing soccer with North Scarborough Soccer Club [N.S.S.C) in Scarborough, Ontario. A club known for creating such talents as Julian de Guzman, formerly of Deportivo de La Coruña, and Jonathan De Guzman of Feyenoord. The team was extremely successful and was granted an invitation to the famed Welsh International Super Cup, formerly known as the Ian Rush Tournament. In the summer of 1997 (NSSC) took part in the Tournament and won their age group. Simpson was named Golden Boot Winner with a staggering 14 goals in 5 matches, landing him second only to Michael Owen for all-time record holder.
The success of the Ian Rush tournament handed Simpson a tryout with Southampton of the Premier League. He would continue to play with North Scarborough until he was 17.
The PSA (Mississauga Eagles FC) proved to be what he needed. The dedication to Total Football and concentration on technique and fitness set them apart from all the other clubs in Toronto. It took a very professional approach in its structuring, training methods, and presentation. The decision to join would pay off when in 2001 P.S.A traveled to Stuttgart, Germany for international exposure and experience. Simpson performed well against the German side, impressing the coach of VfB Stuttgart enough to play with them for the second half. After a brief trial with VfB Stuttgart U19 side, he signed later on that summer and remained with them till the end of 2001.
He started his professional career at the age of 20, when he signed a lengthy deal with the Manchester United F.C. farm team, and Belgium first division side Royal Antwerp FC. The Belgium side paid Ninety nine thousand euros for his services.The deal was set to run till 2005 but troubles arose when the club went through financial difficulty, causing him to leave in the summer of 2002.
In 2003, he returned to Canada to sign with Hamilton Thunder of the Canadian Professional Soccer League. He recorded his first goal for Hamilton on June 7, 2003 against Durham Flames. In his debut season with Steeltown he helped clinch their first piece of silverware by winning the Western Conference title. He featured in the semi-final match against Vaughan Sun Devils, but were eliminated from the playoffs by a score of 2-0. After a contract disputes with the organization he missed the entire 2004 season due to Hamilton owning his player rights.
On April 19, 2005, the Toronto Lynx of the USL First Division signed him to a contract. He made his debut for Toronto on April 23, 2005 against the Portland Timbers. He recorded his first two goals for the Lynx in a 4-4 draw against the Puerto Rico Islanders on May 28, 2005. In 2006, after an impressive season in Toronto he departed to Europe once more to sign with Lombard-Pápa TFC of the Borsodi Liga for a transfer fee of 154.000 £.
He helped the club receive six points at winter break to 24 by the end of the season. Despite the efforts at the end of season Lombard-Pápa were relegated. In the summer of 2006 he became the first Canadian-born player to be signed by Czech giants AC Sparta Prague as one of the biggest Hungarian transfer deals that summer at 352.000 £. In September, he was named to the roster for an UEFA Cup match.
When Michal Bílek became coach within five games into the season ten players changes were made, which included Simpson to be put on loan just one week before the UEFA Cup match against Scottish League giants Hearts. He was loaned to newly promoted SK Kladno for 154.000 £ till winter break to gain more experience of the Czech league. He had an impressive start with SK Kladno scoring in his second game. Playing as an offensive midfielder Simpson supplied the Kladno offense with more opportunities on goal. In a game against FK Teplice, he suffered a horrible head injury which saw him leave on a stretcher. Later it was revealed he suffered a concussion. He missed the entire remaining season, but featured in one match.
Due to the injury, Simpson only played 5 games with SK Kladno. Sparta saw it best to lengthen his loan till the end of the season. Kladno changed his position to a defensive midfield or central midfield role helping keep Kladno in the top division. In the summer of 2007, after playing with Kladno for 7 months he signed for two more years with AC Sparta Prague. Sparta qualified for the Champions League by winning the Czech Cup and league title.
After taking on his option Sparta failed to utilize the striker. Instead they sent him along with Jan Šimák to the reserves. Eventually after the 2007/2008 winter break he went on loan to FK SIAD Most. Simpson was a starter until he suffered a car crash which kept him out of action for two more weeks. Simpson did not play the remainder of the games. Simpson was reportedly linked Nottingham Forest of the English Championship Division after a brief stay at the clubs grounds early May 2008.He broke his contract with Sparta in the summer of 2008.
He signed with Hungarian side Dunaújváros FC. He finished as club top goal scorer with five goals. In February 2009, Dunaújváros folded due to financial problems which led him to sign with Integrál-DAC. During his time with Integrál-DAC he finished with 11 goals as the club's top goal scorer. Integrál-DAC folded in the summer of 2009 leaving him as a free agent.
In July 2010, he was signed by Thai Premier League side Chonburi becoming once more the first Canadian to play in the league. He scored his first goal in his second game against Pattaya United. During his time with Chonburi he won the Thai F.A Cup in 2010. The following he retired from competitive soccer due to injuries. In the winter of 2010 while on winter break from Chonburi, he was diagnosed with Stargardt Eye Disease, a disease which affects the central vision and can cause legal blindness. He had been suffering from the disease since the age of 18, but was unaware of its rare strain in his family.
In April 2011, he came out of retirement to sign with his home club Mississauga Eagles FC of the Canadian Soccer League, and was appointed the team captain. In 2012, he signed with Brantford Galaxy, where he had a good season recording seven goals in ten matches. After the sacking of head coach Ron Davidson eights players along with Simpson sided with Davidson which led to their departure from the team.
Simpson is well known for using his strength and pace while running at players. He creating chances in offensive positions usually facing the goal. Though he has been trained as a striker, most of his success in Europe has been in the midfield as a winger, or offensive midfield. Throughout his career he is experienced in six different positions. Upon signing for Chonburi F.C, he moved to left midfield.
On June 25, 2009 he played as part of the Zinedine Zidane squad in friendly match versus the Canadian All-Stars. Zidane had a part in the tying goal during added time. He passed to his right to Simpson, who found Lewis in front of the goal for the tap in.
He is a former member of U17, U18, and U20 Canadian National Team, appeared in 4 matches scoring 1 goal in 2003. Played with the U20 National Team at the 2003 US Soccer Festival. He has recently been called into Men's National Team camps under two different coaches in the summer of 2006, and most recently to Miami in January 2007. In the summer of 2007, he was part of the player pool for the 2007 Gold Cup.
He was 25 years old when he won his first cap with Canada's senior team on 30 January 2008 (a 1:0 win over Martinique).Club
AC Sparta Prague:
Gambrinus liga Championship: 2007
Champions League Qualification in 2007
Thailand FA Cup Champions in 2010
Simpson is the son of a Portuguese and Bajan mother Ann Knight, and a Jamaican father Bovrell Simpson. His family tree dates back to African heritage. He was born in Toronto, Ontario and raised in North York.
Dave became a father on September 24, 2011 to daughter Jaya Simpson.He married ex Czech model Janelle Nathaniel in 2012.
Simpson to this day is the highest transfer the Toronto Lynx and Lombard-Pápa TFC have ever made and is to date the highest purchase that SK Kladno has ever made per loan spell.He was and remains the only Canadian to ever play for Thai Premier league giants Chonburi F.C.