Hydrothassa hannoveriana is a species of leaf beetle in the family Chrysomelinae.

Hydrothassa hannoveriana grows to 3.5 - 5.0mm in length and are dark metallic blue and orange-yellow or reddish in colour.

These elytral marks may fuse, especially at the rear in females; the median stripe may also be broken or absent.

[2] H. hannoveriana have a scattered distribution in central and northern Europe.

[3] In the United Kingdom it is designated as 'Nationally Scarce' and categorised by the IUCN criteria "vulnerable".