"We would like very much to support Korea in this important issue," Merkel told a joint press conference with President Park Geun Hye, who is on a state visit to Germany.
"Germany was divided for 40 years, Korea is in such a situation in the meantime" as the 1950-53 Korean War concluded with an armistice rather than a peace treaty, which means the two sides technically remain at war.
"Therefore it's our goal and also, a bit, our duty to help others when they would like to establish their national unity," Merkel said.
Dialogue on the issue would be held between the German and South Korean foreign ministries, she added.
Describing herself as a "product" of Germany's reunification after having grown up behind the Iron Curtain, Merkel said that the reunifying process required great economic support.
But she also said openness to people who have lived a very different life was also necessary.
Park said that her country and Germany had a "bond" as they shared the "painful experience" of division, which ended in Germany when the Berlin Wall fell in 1989.
"German unity is for us an example and model for a peaceful reunification," the South Korean president told reporters, through an interpreter.
Park's visit comes a day after she attended a landmark Japan-South Korea summit hosted by US President Barack Obama in The Hague aimed at uniting the three nations against Pyongyang's nuclear threat.
The three-way meeting, held on the sidelines of a nuclear security summit, was followed within hours by nuclear-armed North Korea's test-firing of two ballistic missiles.
Last month, Park vowed to map out a fresh path to Korean reunification, announcing she was setting up a committee under her direct control to work out plans for unifying the long-divided peninsula.
As well as meeting Merkel, Park earlier in the day met President Joachim Gauck, a former East German rights activist and Lutheran pastor.
He was a leading figure in the peaceful revolution that helped topple the Berlin Wall and went on to head the vast archives left behind by the despised Stasi secret police after reunification.
Park has highlighted what she sees as a potential economic "bonanza" to be reaped from the combination of South Korean technical expertise and the North's natural resources.
Most studies however have pointed out the enormous cost of absorbing the impoverished North and pro-merger sentiment in the South, especially among younger people, has waned in recent years.