The men will take on second seeds South Korea, who disposed of Hong Kong 3-0 in Monday's second semi-final.
The women on Tuesday will meet Japan's youthful, attacking team, who secured their first Olympic table tennis medal on Sunday.
China are red-hot favourites in both events, but Germany's men gave them their toughest match of the tournament, prompting an agitated response by coach Liu Guiliang at courtside. The game was a rematch of the Beijing 2008 final.
Timo Boll, Europe's top-ranked player, beat singles gold medalist Zhang Jike, but China still came through 3-1.
"When it got to one match all, we didn't panic," said Zhang, adding ominously: "I feel we're getting better and better."
German coach Jorg Rosskopf said: "Always against the Chinese you get a small, small chance, but it is a long, long way to beat them. We now focus on the bronze match."
South Korea swept past Hong Kong led by Ryu Seung-min, their 2004 Olympic singles champion, who also won his singles encounter.
China's women thumped South Korea 3-0, but they are expecting a far tougher fight against Japan, who many people are tipping to pose a strong challenge to China's dominance - if not in London, then at Rio 2016.
Neither team have dropped a set on their way to the final.
In 19-year-old Kasumi Ishikawa and Ai Fukuhara, 23, second seeds Japan are guaranteed their country's first ever table tennis medal.
"The Japanese have made a lot of progress in the past year," said Shi Zhihao, China's coach. "I think we need to see Japan in a new light. In the past year Fukuhara and Ishikawa have made really steady progress."
Korea's women will play Singapore in Tuesday's bronze medal game, while Germany's men will return on Wednesday for their third-place match against Hong Kong.