Ottelia alismoides

{{Short description|Species of flowering plant}}

{{Speciesbox

| image = Ottelia alismoides - flower view.jpg

| image_caption =

| status = LC

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=Zhuang, X. |author2=Beentje, H.J. |date=2017 |title=Ottelia alismoides |volume=2017 |page=e.T164482A83999434 |doi=10.2305/IUCN.UK.2017-1.RLTS.T164482A83999434.en |access-date=12 November 2021}}

| genus = Ottelia

| species = alismoides

| authority = (L.) Pers.

| synonyms =

• Damasonium alismoides (L.) R.Br.
• Stratiotes alismoides L.

}}

Ottelia alismoides, commonly known as duck lettuce,{{cite book |editor1-last=Lee |editor1-first=Sangtae |editor2-last=Chang |editor2-first=Kae Sun |title=English Names for Korean Native Plants |year=2015 |publisher=Korea National Arboretum |location=Pocheon |isbn=978-89-97450-98-5 |page=556 |url=http://www.forest.go.kr/kna/special/download/English_Names_for_Korean_Native_Plants.pdf |access-date=7 March 2019 |via=Korea Forest Service}} is a species of aquatic plant native to Asia and northern Australia.