国际克莱因蓝（英文：International Klein Blue）是蓝色系之一，在中国常简称为克莱因蓝。因被法国艺术家伊夫·克莱因混合而成和首先得到专利而得名。

伊夫·克莱因早期的事业中广泛地运用克莱因蓝，直到1958年，克莱因开始一系列以克莱因蓝为主要单色题材的艺术品。他让模特儿赤裸身体，染上国际奇连蓝颜料，滚动在空白的帆布中。

International Klein Blue (IKB) is a deep blue hue first mixed by the French artist Yves Klein. IKB's visual impact comes from its heavy reliance on Ultramarine, as well as Klein's often thick and textured application of paint to canvas.