In 2017, the DKP picked up a total of around 11,500 votes nationwide, not enough for a seat. The Marxist-Leninist Party of Germany (MLDP) was more successful with almost 30,000 votes, but still fell miles short of the hurdle to enter parliament. German socialist votes tend to go towards the more moderate Left party (die Linke), which secured 9.2% of the 2017 vote.
German election officials said the DKP had failed to file key paperwork on time.
"Deadlines are deadlines," Federal Election Commissioner Georg Thiel, the committee's chair, was quoted as saying by the DPA news agency.
But their decisions can always be subjected to a legal review.
DKP chairman Patrik Köbele said on Thursday that he plans to appeal in court over the decision.
"We are convinced that this attempt to ban us [from the election] will fail," he said.
Anarchists fail to make the cut
Another fringe party that missed out was the the Anarchistic Pogo Party of Germany, or AAPD, which took part in the 1998 election with the promise to pay voters with free beer.
Running with a slogan "work is s***," election officials also rejected their application to stand because it had only been submitted electronically.
But the South Schleswig Voters' Association, or SSW, had more luck.
The party represents the Danish-speaking minority in Schleswig-Holstein, northern Germany, close to the border with Denmark.