Hamr na Jezeře (German: Hammer am See) is a municipality and village in Česká Lípa District in the Liberec Region of the Czech Republic. It has about 500 inhabitants. It is known as a recreation centre.

The villages of Břevniště and Útěchovice are administrative parts of Hamr na Jezeře.

The name Hamr na Jezeře literally means "hammer mill on Lake".

Hamr na Jezeře is located about 15 kilometres (9 mi) west of Liberec. It lies in the Ralsko Uplands. The highest point is the hill Útěchovický Špičák at 500 m (1,600 ft) above sea level. The Ploučnice River and its arm Hamerská strouha flow through the municipality. The village of Hamr na Jezeře lies on the shores of the Hamerské jezero Pond. This fishpond with an area of 56 ha (140 acres) was established in the 16th century and today is used for recreational purposes and fish farming.

The first written mention of Útěchovice, which is the oldest part of the municipality, is from 1322. Hamr na Jezeře was first mentioned in 1544. In the 16th century, a mill on the Ploučnice and several hammer mills were built in the village to process iron ore mined in the nearby area. At the end of the 19th century, Hamr na Jezeře became a spa village and a tourist destination. This era ended in the mid-20th century, when uranium was mined here for a decade. Since 1993, the village has been a tourist destination again.

Historical population

Year Pop. ±% 1869 833 —     1880 767 −7.9% 1890 693 −9.6% 1900 628 −9.4% 1910 615 −2.1%	Year Pop. ±% 1921 576 −6.3% 1930 624 +8.3% 1950 403 −35.4% 1961 408 +1.2% 1970 397 −2.7%	Year Pop. ±% 1980 341 −14.1% 1991 247 −27.6% 2001 339 +37.2% 2011 394 +16.2% 2021 430 +9.1%
Source: Censuses

Hamr na Jezeře is known as a recreation centre. On the shores of the pond there are two campsites and a swimming pool with complete infrastructure and attractions for tourists. The municipality is sometimes nicknamed "Riviera of the North".

There are no railways or major roads passing through the municipality.

On the Děvín hill, there is a ruin of an eponymous castle. It was a massive royal castle, built in 1250. In the 17th century, it was abandoned, and it was most likely destroyed during the Thirty Years' War.

On the Křížový vrch hill, there is a neo-Gothic Chapel of Our Lady Help of Christians from 1830.

Within Czechoslovakia, Hamr na Jezeře was popularized thanks to the successful 1952 film Dovolená s Andělem.

• Official website