组合型基金（英语：fund of funds，简称FOF），又称为基金中的基金、母基金，是一种特殊的基金，这种基金以其他基金为投资标的，而非直接投资于股票、债券等有价证券。其中有些FOF只投资于同一公司的其他基金，投资者仅需缴纳一层费用。而另一些则会投资于外部基金，此时投资者需缴纳两层费用。

FOF根据所投资基金的不同可以分成各种类型，包括共同基金FOF、对冲基金FOF、私募基金FOF。

组合型基金中还包括私募股权组合基金（private equity fund of funds，简称PEFOF），它是通过对私募股权基金（Private Equity,PE）进行投资，从而对私募股权基金投资的项目公司间接进行投资的基金，即所谓「私募基金的基金」。

A "fund of funds" (FOF) is an investment strategy of holding a portfolio of other investment funds rather than investing directly in stocks, bonds or other securities This type of investing is often referred to as multi-manager investment. A fund of funds may be "fettered", meaning that it invests only in funds managed by the same investment company, or "unfettered", meaning that it can invest in external funds run by other managers.