Stiromesostenus is an Australian genus of ichneumon wasps in the subfamily Cryptinae.

[3] Stiromesostenus ranges from small to moderately large, with forewing length of 4-12 mm.

Most species are reddish brown in colour and several have darkened wing apices.

Stiromesostenus rufus has been reared from an unspecified "fern moth" larva.

[4] An unspecified species of Stiromesostenus have been reared from Uraba lugens (Nolidae)[3]