在计算机科学中，分支（英语：Branch）是在电脑程序中的一段串行代码。它会视情况而运行，主要是看控制流程在这个情况下，是否决定运行它。在高端语言与汇编语言，乃至于机器码写成的程序中，都可以看到分支的存在。在高端语言中，通常会使用条件语句（conditional statement）的形式，把分支包起来，并决定在何种状况下，应该要运行哪一个分支指令。在汇编语言与机器码层级中，则使用跳跃指令（jump instructions），以标记定义出相对应的分支码。

A branch is an instruction in a computer program that can cause a computer to begin executing a different instruction sequence and thus deviate from its default behavior of executing instructions in order. Branch (or branching, branched) may also refer to the act of switching execution to a different instruction sequence as a result of executing a branch instruction. A branch instruction can be either an unconditional branch, which always results in branching, or a conditional branch, which may or may not cause branching, depending on some condition. Branch instructions are used to implement control flow in program loops and conditionals (i.e., executing a particular sequence of instructions only if certain conditions are satisfied).