Eclecticism is a 19th and 20th century architectural style in which a single piece of work incorporates a mixture of elements from previous historical styles to create something that is new and original. In architecture and interior design, these elements may include structural features, furniture, decorative motives, distinct historical ornament, traditional cultural motifs or styles from other countries, with the mixture usually chosen based on its suitability to the project and overall aesthetic value.
The term is also used of the many architects of the 19th and early 20th centuries who designed buildings in a variety of styles according to the wishes of their clients, or their own. The styles were typically revivalist, and each building might be mostly or entirely consistent within the style selected, or itself an eclectic mixture. Gothic Revival architecture, especially in churches, was most likely to strive for a relatively "pure" revival style from a particular medieval period and region, while other revived styles such as Neoclassical, Baroque, Palazzo style, Jacobethan, Romanesque and many others were likely to be treated more freely.
Eclecticism came into practice during the late 19th century, as architects sought a style that would allow them to retain previous historic precedent, but create unseen designs. From a complete catalogue of past styles, the ability to mix and combine styles allowed for more expressive freedom and provided an endless source of inspiration. Whilst other design professionals (referred to as 'revivalists') aimed to meticulously imitate past styles, Eclecticism differed, as the main driving force was creation, not nostalgia and there was a desire for the designs to be original.
File:10. Городківка (Костел Святої Клари).jpg|[[Church of St. Clare, Horodkivka]], Ukraine, built 1910–1913, blending elements of neo-Gothic and modern twentieth century architecture
File:Carson Mansion Eureka California.jpg|The [[Carson Mansion]], [[Eureka, California]] in the American style called [[New World Queen Anne Revival architecture|Queen Anne Revival architecture]].