| Official Name: | Karlholmsbruk |
| Pushpin Map: | Sweden Uppsala#Sweden |
| Subdivision Type: | Country |
| Subdivision Name: | Sweden |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Tierp Municipality |
| Subdivision Type2: | County |
| Subdivision Name2: | Uppsala County |
| Subdivision Type1: | Province |
| Subdivision Name1: | Uppland |
| Area Footnotes: | [1] |
| Area Total Km2: | 2.37 |
| Population As Of: | 31 December 2010 |
| Population Total: | 1,150 |
| Population Density Km2: | 485 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 60.5167°N 54°W |
Karlholmsbruk is a locality situated in Tierp Municipality, Uppsala County, Sweden with 1,150 inhabitants in 2010.
In 1725 Charles de Geer of Lövstabruk purchased the mansions of Finnerånger, from Johan Dahl Finnerånger, and Holmsånger, from Hugo Johan Hamilton Holmsånger, in order to start an ironworks, Karlholmsbruk, at the mouth of Tämnarån, which he successfully did after a lengthy legal process. Originally a Wallonic hearth was erected. In 1880 it was replaced by a Lancashire hearth. Iron production was discontinued in September 1932.[2]