选择性剪接（英语：Alternative splicing；又称“可变剪接”）是基因表达的方式，在人类细胞是非常普遍的。真核细胞的基因串行中，包含了内含子（intron）与外显子（exon），两者交互穿插。其中内含子在基因转录成mRNA前体后会被RNA剪接体移除，剩下的外显子才是能够存在于成熟mRNA（之后再进一步转译成蛋白质）的片段。

而选择性剪接便是利用这样的特性，一条未经剪接的RNA，含有的多种外显子被剪成的不同组合，可转译出不同的蛋白质。就能将同一基因中的外显子以不同的组合方式来表现，使一个基因在不同时间、不同环境中能够制造出不同的蛋白质（基因表达调控），可增加生理状况下系统的复杂性或适应性。

Alternative splicing is a regulated process during gene expression that results in a single gene coding for multiple proteins. In this process, particular exons of a gene may be included within or excluded from the final, processed messenger RNA (mRNA) produced from that gene. Consequently, the proteins translated from alternatively spliced mRNAs will contain differences in their amino acid sequence and, often, in their biological functions (see Figure). Notably, alternative splicing allows the human genome to direct the synthesis of many more proteins than would be expected from its 20,000 protein-coding genes. Alternative splicing is sometimes termed differential splicing.