| Pétur J. Thorsteinsson | |
| Birth Date: | 4 June 1854 |
| Birth Place: | Otradalur, Danish Iceland |
| Death Place: | Hafnarfjörður, Kingdom of Iceland |
| Spouse: | Ásthildur Guðmundsdóttir |
Pétur Jens Thorsteinsson (4 June 1854 - 27 July 1929) was an Icelandic businessman, merchant and entrepreneur.[1] He was one of the key founders of Milljónarfélagið along with Thor Jensen.[2]
Pétur was married to Ásthildur Guðmundsdóttir. Their children include artist Muggur and footballers Samuel Thorsteinsson, Gunnar Thorsteinsson and Friðþjófur Thorsteinsson.[3]