国际天球参考框架 (International Celestial Reference Frame，ICRF) 是一个依据212个银河系外来源 (主要是类星体) 创建的中心位于太阳系的重心座标准惯性参考框架。虽然相对论意味着没有真正的惯性框架，但是用来定义ICRF的银河系外来源的距离是非常的遥远，因此基本上可以将它们任何的角运动视为零。ICRF现在是用来定义行星 (包括地球) 和其它天体位置的标准参考框架。这个框架在1998年1月1日得到国际天文学联合会的认可。

请注意，在天文测量，参考框架是参考物理现实的系统，也就是说，参考框架是报告座标的基准点。ICRF是现实的国际天球参考系统，并且是精确度较低的第五基本星表 (FK5) "J2000.0"认同的原始框架。

The International Celestial Reference Frame (ICRF) is a quasi-inertial frame of reference centered at the barycenter of the Solar System, defined by the measured positions of 212 extragalactic sources (mainly quasars). Although general relativity implies that there are no true inertial frames around gravitating bodies, the ICRF is important because it definitely does not exhibit any measurable angular motion since the extragalactic sources used to define the ICRF are so far away. The ICRF is now the standard reference frame used to define the positions of the planets (including the Earth) and other astronomical objects. It has been adopted by International Astronomical Union since 1 January 1998. ICRF had a noise floor of approximately 250 microarcseconds (µas) and an axis stability of approximately 20 µas; this was an order-of-magnitude improvement over the previous Fifth Fundamental Catalog (FK5).