Sieboldius is a genus of dragonflies in the family Gomphidae. The genus occurs in Asia and is closely related to the dragonhunter (Hagenius brevistylus) of North America.

The genus contains the following species:

• Sieboldius albardae Selys, 1886
• Sieboldius alexanderi (Chao, 1955) - small dragonhunter
• Sieboldius deflexus (Chao, 1955)
• Sieboldius gigas (Martin, 1904)
• Sieboldius herculeus Needham, 1930
• Sieboldius japponicus Selys, 1854
• Sieboldius maai Chao, 1990
• Sieboldius nigricolor (Fraser, 1924)

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