Here are some well-known Jain temples and derasars in Europe, mainly in the United Kingdom:

• Jain Centre Leicester / Jain Samaj Europe, Leicester — described as the first Jain temple outside India and a major Jain centre in Europe. ( jaincentreleicester.com)
• Oshwal Centre Derasar, Northaw, Hertfordshire — the Oshwal Centre has a beautiful temple/derasar; it is also described as Europe’s first Shikharbandh Jain Temple. ( oshwal.org.uk)
• Oshwal EKTA Centre, Kingsbury, London — one of the Jain venues run by the Oshwal Association of the U.K. ( oshwal.org.uk)
• Shree Mahavir Swami Jain Temple, Harrow, London — a Digambar Jain temple in London. ( jainmandir.org)
• Shri Kailashgiri Digamber Jain Temple, Hounslow, London — a Digambar Jain temple in London. ( jainmandir.org)
• Jain Derasar, Kenton, Middlesex, London — a Jain derasar in London associated with Mahavir Foundation. ( jainmandir.org)
• Jain Ashram / International Mahavir Jain Mission, Birmingham — the ashram also functions as a Jain temple. ( jainmandir.org)

If you want, I can also give a country-wise list of Jain temples in Europe.