Roztoky u Semil is a municipality and village in Semily District in the Liberec Region of the Czech Republic.

It is a common Czech geographical name for places founded at the confluence of a small stream with a larger watercourse.

The highest point is the hill Buč at 652 m (2,139 ft) above sea level.

The first written mention of Roztoky is from the period 1356–1360, when the monastery in Hradiště sold the village to Lords of Lemberk.

Among the protected cultural monuments in the municipality are four stone statues: Our Lady of the Immaculate Conception (created in 1728), Virgin Mary of Karlov (1760), Virgin Mary of Bozkov (1767), and Saint John of Nepomuk (second half of the 19th century).