| Country: | England |
| Official Name: | Reeth Bay |
| Civil Parish: | Niton and Whitwell |
| Coordinates: | 50.58°N -1.28°W |
| Static Image Name: | File:Reeth Bay, Isle of Wight, UK.jpg |
| Static Image Caption: | Reeth Bay |
| Map Type: | Isle of Wight |
| Region: | South East England |
| Hide Services: | yes |
Reeth Bay is a small curved bay on the southernmost tip of the Isle of Wight, England. It lies to the south of the village of Niton with a NaNadj=mid1adj=mid shoreline. It faces south out into the English Channel and lies to the east of St. Catherine's Point lighthouse. It is at the centre of a small hamlet called Castlehaven where there is a concrete ramp for launching small craft.[1] The beach is predominantly sand and pebbles. The seabed is a mixture of rocks and mud. The bay is best accessed from the road from Niton that leads down to the bay.
There is a 19th-century lifeguard cottage at the bay.[2] The bay used to be a popular tourist destination and had bathing machines during the Victorian era. There also used to be an east-facing slip at Puckaster for fishing boats.