Fyris
{{Short description|River in Uppland, Sweden}}
{{Infobox river
| name = Fyris River
| name_native = {{native name|sv|Fyrisån}}
| name_other =
| name_etymology =
| image = Uppsala - View of river and Västgöta nation.jpg
| image_size =
| image_caption = The Fyris River in winter as seen from a hotel window in central Uppsala.
| map =
| map_size =
| map_caption =
| pushpin_map =
| pushpin_map_size =
| pushpin_map_caption=
| subdivision_type1 = Country
| subdivision_name1 = Sweden
| subdivision_type2 = County
| subdivision_name2 = Uppsala
| subdivision_type3 = County
| subdivision_name3 =
| subdivision_type4 =
| subdivision_name4 =
| subdivision_type5 =
| subdivision_name5 =
| length_km = 80
| length_ref = {{cite encyclopedia | title=Fyrisån | encyclopedia=Nationalencyklopedin | url=http://www.ne.se/fyrisån | language=Swedish | accessdate=11 July 2010}} {{Subscription required}}
| width_min =
| width_avg =
| width_max =
| depth_min =
| depth_avg =
| depth_max =
| discharge1_location=
| discharge1_min =
| discharge1_avg = {{convert|14|m3/s|cuft/s|abbr=on}}
| discharge1_max =
| source1 = Sundbro River
| source1_location = Östhammar Municipality
| source1_coordinates= {{Coord|60.206|17.893|format=dms|display=i}}
| source1_elevation = {{Convert|0|m|abbr=on}}
| mouth = Mälaren
| mouth_location = Uppsala
| mouth_coordinates = {{coord|59|47|12|N|17|39|20|E|display=inline,title}}
| mouth_elevation = {{Convert|2|m|abbr=on}}
| progression =
| river_system =
| basin_size_km2 = 1982
| tributaries_left =
| tributaries_right =
| custom_label =
| custom_data =
| extra =
}}
File:River Fyris.jpg (August 2022)]]
Fyrisån ({{IPA|sv|ˈfŷːrɪsˌoːn}}, "the Fyris river") is a river in the Swedish province of Uppland, which passes through the city of Uppsala and ends in Lake Mälaren.
The "Sala" river in Uppland was changed in the 17th century in memory of the Fyrisvellir battle, mentioned in the Icelandic sagas, as it was the belief that the marshy plains called "Föret" was the site of the famous Battle of Fýrisvellir in the late 10th century.
Boats can sail up the river from Lake Mälaren all the way to central Uppsala where two weirs make further progress impossible. In the summer of 2007, the construction of a fish ladder began{{cite web |url=http://www2.unt.se/avd/1,1786,MC=77-AV_ID=689382,00.html |title=Aspen får trappa i Islandsfallet |accessdate=24 December 2007 |author=Daniel Jansson |date=2007-11-22 |publisher=Upsala Nya Tidning |language=Swedish |url-status=dead |archiveurl=https://web.archive.org/web/20071123173454/http://www2.unt.se/avd/1%2C1786%2CMC%3D77-AV_ID%3D689382%2C00.html |archivedate=23 November 2007 }} to enable the asp, an endangered and potamodromous fish, to pass the weirs and reach its spawning waters. On the last day of April every year, during The Uppsala River Rafting Event, students attempt to navigate the weirs on homemade rafts with predictable results.