Lahti is a Finnish surname meaning "bay" or "gulf".
Geographical distribution
As of 2014, 65.6% of all known bearers of the surname Lahti were residents of Finland (frequency 1:737), 22.0% of the United States (1:144,270), 7.6% of Sweden (1:11,357) and 2.4% of Canada (1:133,326).
In Finland, the frequency of the surname was higher than national average (1:737) in the following regions: 1. South Ostrobothnia (1:295) 2. Central Ostrobothnia (1:318) 3. Pirkanmaa (1:437) 4. Central Finland (1:488) 5. Tavastia Proper (1:517) 6. Satakunta (1:532) 7. Southwest Finland (1:582) 8. Kymenlaakso (1:721)