This paper provides a geometric analysis of brick patterns used as Islamic and decorative elements in Anatolian Seljuk mosques. Brick monumental architecture was introduced to Anatolia by the Seljuk Empire, which had a mixed architectural culture influenced by the technique of exposed laying bricks in planned patterns, originating in Iran. The Seljuk period, spanning the 11th to 13th centuries, marks a significant era in Anatolian architecture where brick masonry, though less common than stone masonry, stood out for its rarity and uniqueness. Brick masonry in Seljuk architecture is distinguished by its versatility and adaptability. Seljuk artisans and architects employed various brick-bonding techniques to create intricate designs. Kufic inscriptions adorned mosque facades and interiors, where bricks were arranged into geometric Arabic script that continued from the center outward according to specific rules. Two-dimensional geometric decorative surface decorations, specially designed dome and minaret structures, and other three-dimensional decorative elements such as muqarnas were crafted with brick, adding visual complexity and structural integrity to the buildings. The study examines different types of bricks used in Seljuk architecture, focusing on their shapes, sizes, and surface treatments. Various types of bricks, including standard rectangular bricks, square bricks, and specially shaped bricks, were used to create intricate patterns and designs. Dimensions and surface treatments, including turquoise glazing, played crucial roles in the aesthetic outcomes of the masonry. This research primarily aims to analyze the geometric principles underlying these brick patterns and their symbolic meanings within Islamic art. Understanding the technical and artistic brickwork methods used by the Seljuks is essential for preserving this tradition and inspiring contemporary architectural practices. Seljuk brick masonry's enduring beauty and functionality offer valuable lessons for modern architecture, particularly in integrating traditional elements with contemporary design.