在数学中，解析函数是局部上由收敛幂级数给出的函数。解析函数可分成实解析函数与复解析函数，两者有类似之处，同时也有重要的差异。每种类型的解析函数都是无穷可导的，但复解析函数表现出一些一般实解析函数不成立的性质。此外在超度量域上也可以定义解析函数，这套想法在当代数论与算术代数几何中有重要应用。一个函数是解析函数当且仅当这个函数在它定义域内的每个x₀的邻域内的泰勒级数都收敛。

解析函数集有时也写作 。

In mathematics, an analytic function is a function that is locally given by a convergent power series. There exist both real analytic functions and complex analytic functions, categories that are similar in some ways, but different in others. Functions of each type are infinitely differentiable, but complex analytic functions exhibit properties that do not hold generally for real analytic functions. A function is analytic if and only if its Taylor series about x₀ converges to the function in some neighborhood for every x₀ in its domain.