Iberochondrostoma olisiponensis, the Lisbon arched-mouth nase, is a freshwater fish discovered in 2007 in the lower Rio Tejo basin, Portugal.

It can be distinguished from the other Iberian nase species by the lack of horny blade on the lower jaw, the absence of intense reddish coloration at the base of the fins and by its pronouncedly arched mouth.

It is further distinguished from Iberochondrostoma lusitanicum, a phylogenetically close species that lives in the same area, by having a higher body, a relatively longer head, and a larger eye.

Unlike the other phylogenetically related species, the Lisbon's arched-mouth nase shows external sexual dimorphism, with males having longer pelvic fins whose extremities pass the anus and often overlap with the anal fin.

It was estimated from a molecular clock that the species had split 7.9-12.5 million years ago (middle–upper Miocene) from its most recent ancestor.