Fu Deng (343–394) is an emperor of the Chinese/Di state Former Qin.

He assumes the throne in 386 after the deaths of Fu Jiān (Emperor Xuanzhao) and Fu Jiān's son Fu Pi (Emperor Aiping), even though he is only a distant relative of theirs, as by that time Former Qin's territory has largely been reduced to the territory under his control.

He battles the Later Qin emperor Yao Chang for years in a stalemate in which neither can conclusively prevail, but in 394, he mounts a major attack on Later Qin after Yao Chang's death, seriously underestimating Yao Chang's son and successor Yao Xing, who captures and executes him.

Later this year, his son Fu Chong, who succeeds him, dies in battle, ending Former Qin.