Olszewo may refer to the following places:

• Olszewo, Gmina Boćki in Podlaskie Voivodeship (north-east Poland)
• Olszewo, Gmina Brańsk in Podlaskie Voivodeship (north-east Poland)
• Olszewo, Łomża County in Podlaskie Voivodeship (north-east Poland)
• Olszewo, Siemiatycze County in Podlaskie Voivodeship (north-east Poland)
• Olszewo, Łódź Voivodeship (central Poland)
• Olszewo, Masovian Voivodeship (east-central Poland)
• Olszewo, Konin County in Greater Poland Voivodeship (west-central Poland)
• Olszewo, Kościan County in Greater Poland Voivodeship (west-central Poland)
• Olszewo, Środa Wielkopolska County in Greater Poland Voivodeship (west-central Poland)
• Olszewo, Działdowo County in Warmian-Masurian Voivodeship (north Poland)
• Olszewo, Gmina Prostki in Warmian-Masurian Voivodeship (north Poland)
• Olszewo, Gmina Stare Juchy in Warmian-Masurian Voivodeship (north Poland)
• Olszewo, Mrągowo County in Warmian-Masurian Voivodeship (north Poland)
• Olszewo, Nidzica County in Warmian-Masurian Voivodeship (north Poland)
• Olszewo, Olecko County in Warmian-Masurian Voivodeship (north Poland)