Papadopoulos started his career from the youth academies of Greek minnows Akratitos, and made his debut in 1999, contributing to the team's promotion to Alfa Ethniki in 2001 for the first time in its history.

During the next summer, Celta Vigo signed striker David Rodríguez and winger Quique de Lucas in order to strengthen the squad.

At the beginning of the 2010–11 season, Celta Vigo's manager Paco Herrera claimed that he would not count with Papadopoulos any more,[7] putting pressure on him to leave the club due to his high salary and his poor performances.

In January 2012, Papadopoulos moved on loan to Levadiakos of the Greek Super League,[8] but he failed to score a goal although the team finished in 7th place.

On 11 November 2012, Papadopoulos scored his fourth goal of the season against Asteras Tripolis giving the victory to Panthrakikos and he was elected Man of the Match.

PSAP spokesman Stamatis Sirigos added: "With his character, leadership skills and experience, Dimitros Papadopoulos helped his team-mates and boosted their confidence.

[10] On the other hand, Papadopoulos put several frustrating campaigns behind him : "I always believed I could get my career back on track," he said at Monday's award ceremony in Athens.

"[11] After a great season, in the summer of 2013 he signed a two-year contract with Atromitos,[12] a team that got 4th place in the previous year of Greek Superleague.

On 30 August 2013 in a dramatic game against AZ Alkmaar for the Europa League, the latter beat Atromitos after fire caused a delay in playing the remaining 33 minutes.

Spectators were evacuated after the match was halted in the 57th minute, with Atromitos leading 1–0, but trailing 3–2 on aggregate, through a goal from Dimitris Papadopoulos before play was stopped.

When the action resumed next day, Thanasis Karagounis made it 2–0 in the second leg but the Greek team could not find a winning goal as the tie ended 3–3 on aggregate, with the Dutch side advancing into the group phase.

[13] On a 0-0 cup game against the Greek giant Olympiacos after an excellent appearance, he said in front of TV : "We have a good team confronting any opponent.

[16] On 29 August 2014, Papadopoulos, although, he was linked with Veria as they had an oral agreement, signed a contract with Superleague Greece team PAOK for one year.

On 18 October 2015, in his first match in the 2015-16 season as a member of the starting XI, he missed a penalty in a 1–1 home draw against Skoda Xanthi as the ball hit the crossbar.

[29] Dimitrios Papadopoulos made his debut in the Greece national team on 20 November 2002 against Republic of Ireland and he was included in the squad of Euro 2004 that would go on to be tournament champions.

His pass for the goal of Zisis Vryzas allowed Greece to qualify from the group stage at the expense of Russia and Spain and then become Euro 2004 Champions.

On 29 August 2013, the coach of the Greece national team, Fernando Santos announced the return of Dimitrios Papadopoulos after six years absence[30] for the match against Liechtenstein in Vaduz at the Rheinpark Stadion stadium for the 2014 FIFA World Cup qualification.