1988 - 1992 Brondby IF
1992 - 1996 FC Barcelona
1994 - 1995 Southampton (loan) 17 games 5 goals
1995 - 1996 Manchester City 4 games
1996 Coventry City (loan)
1996 - 1999 Odense
1999 - 2000 Toulouse
2000 - 2001 Walsall 9 games 1 goal
2001 - 2004 San Jose Earthquakes 91 games 11 goals
2005 California Cougars

1990 - 1993 Denmark U21 21 games and 3 goals

Ekelund started his professional career with Danish club Brøndby IF in 1988. He made his first team debut at the age of 15, becoming the youngest player ever to appear in the top-flight Danish 1st Division. He was named 1988 Danish under-17 Talent of the Year. Ekelund was a part of the 1990 and 1991 Danish championship winning Brøndby team, and was called up for the Danish under-21 national team.

He impressed with the Denmark under-21 team in the 1992 Summer Olympics hosted at Barcelona, and was soon off to defending Spanish La Liga champions FC Barcelona. He joined Danish-Spaniard Thomas Christiansen at FC Barcelona B, the second-string team of the club. Due to league restrictions on the number of foreigners in the playing line-up, Ekelund had a hard time displacing stars like Michael Laudrup, Hristo Stoichkov and Romario in the Barcelona attack. He played a single league match during the 1993-94 season, before leaving the club.

Ekelund went to England, to Premiership club Southampton. He joined the club after the 1994 pre-season, when both Southampton and Barcelona were holding a training camp in Holland and stayed at the same hotel. Southampton coach Alan Ball and FC Barcelona's Dutch manager Johann Cruyff were old friends and had taken family holidays together. Cruyff walked in during the team's evening meal, and chatted with the players and his old friend Alan Ball. After a long chat, he finally said he had to leave and be with his squad, and asked Ball what gift he wanted: he replied "a left sided midfielder"; Cruyff told him "No problem. I will leave one in the morning". In the morning, the Saints coach found a player in full Barcelona tracksuit in the hotel lobby, his name was Ronnie Ekelund, and the rest they say is history.

Ekelund was an instant hit at Southampton's The Dell stadium, forming a great partnership with English mifielder Matthew Le Tissier. He was skillful with the ball, had great pace, clever movement and superb finishing ability. At first, Saints wondered why Barcelona had let him go so easily, but the reasons soon became clear when it emerged that Ekelund was carrying a back injury. The Southampton medical team felt that this could only be cured by surgery, but Ekelund refused to "go under the knife"; this disagreement put paid to any hopes of a permanent transfer deal.

Ekelund underwent brief loan deals at English clubs Manchester City and Coventry City, but injuries limited his playing time there. He went back to Denmark in 1996, playing for Odense BK. He had stints with French club Toulouse FC and English team Walsall F.C., before leaving Europe in 2001.

In 2001, Ekelund transferred to San Jose Earthquakes in Major League Soccer, where he was ever-present in the starting lineup. In four seasons with San Jose, he scored 11 goals (five of them penalty kicks) and made 16 assists in the regular season. He also scored a goal and made four assists in the playoffs. He helped the team win the MLS Cup title in 2001 and 2003. Ekelund was named in the MLS Best XI in 2002. He left the team after the 2004 MLS season. Ekelund made the move to indoor soccer in 2005 joining the California Cougars who are coached by his good friend and former teammate Troy Dayak.