As the first application of the Renaissance Humanist concept of urban design, the town occupies a seminal position in the development of the concept of the planned "ideal town" and plays a significant role in subsequent urban development in Italy and beyond." (OUV) – "The application of the principle of the Renaissance "ideal city" in Pienza, and in particular in the group of buildings around the central square, resulted in a masterpiece of human creative genius." (OUV – criterion i)

Sabbioneta

Project was planned, but never constructed

The Silk factory etc was intended to be part of the utopian town of Ferdinandopolis

"The model town was an important aspect of imperial policy for the British, to provide the functional space thought necessary for the smooth working of a colony"

"A unique example of a Renaissance town in Central Europe, consistently designed and built in accordance with the Italian theories of the "ideal town," on the basis of a plan which was the result of perfect cooperation between the open-minded founder, Jan Zamoyski, and the outstanding architect, Bernardo Morando. (Wiki)

Grand Hornu: designed as an 'ideal city' at the very beginning of the Industrial Revolution on the European Continent (1810-20) (AB ev)

The city of Aranjuez was developed as an Enlightened City from 1750 on, with strict geometry.

The town was almost entirely destroyed by fire in 1794 and had to be rebuilt from scratch. "Rationalist" principles were adopted which addressed the relationship between living conditions and "health". A town plan was developed in 1835 "designed by one of Pestalozzi's pupils (Charles-Henri Junod) and inspired by an ideal town called "Sonnenstadt", planned in 1824 by a Dr Bernhard Christoph Faust. Features included having most houses facing onto small gardens receiving the midday sun.
See de.wikipedia.org

Conceived as an Ideal City, planned for this purpose by the Emperor Hadrian (AB ev)

example of an ideal Protestant city (AB ev)

Marienberg

The towns and the way people lived and worked together was seen as utopian by some.

The Jesuits were inspired by the humanist Ideal City idea (AB ev)

From the beginning of the 19th century, the new town of Františkovy Lázně "was further expanded, based on the principle of ideal towns, to form a regular rectangular grid within which the principal functions of the spa were concentrated." (Ab Ev)

Oranienbaum

Longwy and Neuf-Brisach
See meinfrankreich.com

"The humanist concept of the 'ideal city' came to life here in the neighbourhoods built from 1492 onwards by Biagio Rossetti according to the new principles of perspective." (Official description)

Engineers (...) such as Johannes van den Bosch, the initiator of the Colonies of Benevolence, (...) were familiar with the ideas of the città ideale (...). In the Netherlands, the ideas of Flemish engineer Simon Stevin on settlements had played a significant role, in particular his 'Ideal Plan for a City' (...). Form follows function was a basic principles in land reclamation since the middle ages, resulting in straight lines and standard plots. The Colonies can be seen in light of this tradition of landscape planning in the Netherlands, supplemented by contemporary ideas on creating new settlements. (Nomination file, p. 75)

"In the 17th and 18th centuries, Amsterdam was seen as the realization of the ideal city that was used as a reference urban model for numerous projects for new cities around the world." (SOV statement)