The circle form has always fascinated artists throughout history and has played an important role in the creation of works of art. This form is often used to depict nature and still life, and at the same time, it is the main element of Abstract compositions. Beyond its aesthetic appeal, the circle embodies deep meanings that help interpret the content of works of art. This study initially examines the representation of the circle form in the works of painters of early modernism. Subsequently, it traces the evolution of this form in Abstract paintings. To address these goals, this research seeks to answer several key questions: What role does the circle play in the works of artists of early modernism? How do these works compare in terms of similarities and differences with Abstract art? What are the underlying factors affecting the emergence of the role of the circle in the works of artists of the two periods?The spiritual developments that paved the way for modernism in the fine arts, occurred in the closing decades of the 19th century. The significant advances made by leading figures of modernism, including Monet, Cézanne, and Van Gogh, led to a revival of visual aesthetics and a profound shift in the interpretation of the artistic process (Bocola, 2014, p. 100). Over time, and with the emergence of different styles of painting, the term Abstraction emerged. This concept, introduced within the context of modern Western art, marked a fundamental departure from the representational aspects that had defined naturalistic art in various styles and movements. As a result, this shift initiated a transformative movement in the 20th century in which artists who championed Abstract art claimed to be able to convey a range of human experiences, such as mental processes, emotions, and unique thoughts, without relying on the depiction of recognisable external subjects (Ravanju & Pedram, 2021).The present study was conducted using a descriptive-analytical method, with library data collection and purposive sampling. The statistical sample of this study includes eight paintings by artists such as Claude Monet, Vincent Van Gogh, Paul Cézanne, Wassily Kandinsky, and Hilma af Klint. The early stage of modernism, characterised by movements such as Impressionism and Post-Impressionism, represents a progressive integration of scientific perspective and contemporary philosophical thought. The aim of Impressionist artists was to convey to their audience the concept of forms immersed in a luminous space, which required extensive exploration of light as a fundamental element affecting our perception of colour. Thus, in the twentieth century, building on the advances of visual artists in the nineteenth century, a significant transformation in the realm of art called "Abstract art" took place.In contemporary art movements, the "circle" serves as a fundamental element for the development and valorisation of Abstract art, cubism, and movements such as structuralism and Orphism, and is even the foundation of the Impressionist movement (Dobokor, 1994, p. 110). Monet is known as a pioneering figure of Impressionism, who used natural outdoor light to express the instantaneous changes of landscapes as they were illuminated by sunlight (Wang , 2022). In his “Sunrise”, he used the complementary colours of blue and orange, placing the sun as an orange circle on a blue background. Despite its small size, the circle acts as the focal point of the composition due to the striking contrast it creates with the surrounding blue. It should be noted that in the Impressionist movement, the accurate depiction of the physical qualities of light was considered a fundamental principle of painting. As a result, it is not surprising that the circular shape of the sun, representing light and radiance, often appears in the landscapes of Impressionist painters. Claude Monet, in line with his contemporaries, praised the beauty of sunlight and transformed the sun into a luminous ring (Dobokor, 1994, p. 111).Another early modernist artist who used the circle to depict the sun in his works was the Post-Impressionist painter Vincent van Gogh. The circular disk of the sun was one of Van Gogh's favourite subjects. Van Gogh's "The Extravagant" is bathed in light that shines from a huge halo that the painter's pen has drawn in the form of concentric circles. This luminous circle illuminates the cultivated land, indicating that the wheat ears are bearing fruit. Van Gogh seems to have shown in his paintings the presence of the Christian sun in the lives of the weakest social classes (Villas Boas, 2024, p. 20). In this way, it demonstrates the bond and friendship between religion and people. Van Gogh states: "If light is a symbol of goodness and truth, then the sun, which is the most important source of light, must be one with God." (Dobokor, 1994, p. 111). This analysis suggests that the importance of light, especially the sun, which is depicted as a luminous circle, is deeply rooted in Van Gogh's religious upbringing. He saw the source of light as a divine being, which influenced the brightness of his artwork.Cézanne was another artist whose goal was to strengthen the foundations of Impressionism, which led him to explore the theory of colour and form and integrate theoretical concepts with practical application (Pakbaz, 2017, p. 313). The sphere or circle is one of the three forms that Paul Cézanne envisioned as the fundamental shapes that make up the universe. He recreates nature using cylinders, cones, and spheres, ensuring that in three-dimensional space, the edges of every object and every view tend toward a central point. As a result, after prolonged observation and exploration, the viewer's gaze is focused. Cézanne believed that within every orange, apple, marble, and container, there is a focal point (Dobokor, 1994, p. 111).Klint was a prominent artist known for his landscapes and portraits in the late 19th and early 20th centuries. Klimt's fame among American audiences was further enhanced by his appearance in an exhibition titled "The Spiritual in Art: Abstract painting" held in 1986 (Ohrner, 2019). Unlike Kandinsky, Mondrian, and Malevich, whose artworks were influenced by spirituality, Klint considered spirituality to be the core essence of her artistic practice (Isenberg, 2020). She created a series of paintings consisting of forms of circles, ovals, and spirals that depicted supernatural force (Furio, 2014). One of these series was based on the discovery of the atom and its impact on the artist. All of these developments and changes had a direct impact on the creation of works by artists such as Klimt. He frequently organised his Abstract works into series, each with recognisable titles that reflected his deep interests in both science and spirituality, such as Atom and Parsifal (Friedman, 2020).The results of this study show that analysing works of art from two distinct periods reveals a noticeable evolution in the expressive techniques employed by artists, which can be attributed to changes in lifestyle, personal and religious beliefs, culture, and scientific discoveries. In early modernist works, the circle form was mainly used to depict tangible and observable shapes, while Abstract works, influenced by cultural influences and inspired by pioneering discoveries such as the discovery of the atom, began to explore unfamiliar territories.