Chancellor Angela Merkel has paid tribute to the group of army officers who hatched the plot, including Claus von Stauffenberg, who placed the bomb inside the Fuhrer's bunker in July 1944.
“Those who acted on July 20 are an example to us,” Ms Merkel said in a video message.
“They followed their conscience and thereby shaped a part of Germany's history that otherwise would have been solely defined by the darkness of National Socialism.”
A series of unfortunate coincidences led to the failure of the plot, which left Hitler with a perforated eardrum but no other injuries.
Ms Merkel is due to attend the annual swearing-in ceremony for 400 new soldiers before addressing a memorial held in the courtyard of the Bendlerblock, the central Berlin building where Stauffenberg and his fellow dissidents both planned their coup attempt and were executed after its failure.
The building now houses the German Resistance Memorial Centre, a museum dedicated to those who tried to fight back against the Nazi regime.
The relatively small number of people who did organise resistance to the Third Reich, including the officers involved in the 20 July bomb plot, were initially seen by most Germans as traitors and largely forgotten for decades,
It took until the 21st century for a survey to show most modern-day Germans now agreed honouring the anti-Nazi movements was “important for German political culture”.
The Stauffenberg plot became internationally famous after it was turned into a Hollywood film in 2008, with Tom Cruise playing the famous bomber.
Stauffenberg, an aristocratic officer who had slowly become disillusioned with the Nazis’ conduct of the war, joined a loose group of 200 to 300 officers who made detailed plans to take over the government after killing Hitler.
He smuggled two bombs hidden in briefcases into a meeting planned for Hitler’s Eastern Front headquarters on 20 July 1944, planning to leave them close to the Fuhrer inside the concrete and steel meeting room underground.
However, he was only able to arm one of the bombs and the hot weather meant the meeting was moved upstairs to a less confined wooden building.
At the last moment, after Stauffenberg had excused himself, another aide shifted the briefcase bomb behind a heavy wooden table leg. As a result, although the blast killed four people and injured dozens of others, it failed to seriously injured Hitler.
Ms Merkel said although the plotters failed, Germany owed them a debt of gratitude for trying to end the horrors of the fascist regime. She also said Germans today must emulate their resistance to the far-right.
“Today, we are obliged to confront all tendencies that want to destroy democracy — including right-wing extremism.”
She specifically mentioned the recent murder of Walter Lübcke, a politician who was believed to be have been shot in the head by a far-right sympathiser because of his pro-migration policies.
The granddaughter of one of Stauffenberg’s co-conspirators has used the anniversary to call for 20 July to become a public holiday in Germany.