Angel Investing provides systematic and comprehensive review of the large body of research literature on angel investors. Based on the analysis and consideration of previous literature reviews, the authors created an organizing framework that captures the major aspects of the angel investment landscape including the major perspectives in angel investing: the angel investors (including angel networks and angel groups), the entrepreneurs and their ventures, the relationship and decision-process between angels and entrepreneurs, and performance. Angel Investing begins with a look at the angel investors themselves and the market characteristics that lead to angel investing. Section 2 focuses on the contributions made by angels as well as subgroups of angel investors, such as women and micro-angels. Section 3 discusses angel networks and public policy implications. Section 4 explores different typologies of angels, focusing on their reasons for investing and on some differences between angel investors and venture capitalists. Section 5 shifts focus to examine the other side of the dyad - the entrepreneurial firms - and reviews the literature that explores the firms that are seeking angel money. Section 6 moves back to the angels examining the decision making process in angel investing. Section 7 reviews the articles that look at angel investor and firm performance. Section 8 reviews the methodologies used by the researchers in the angel investor literature, thereby illustrating how the data collection and analytic tools have both changed and remained the same over time and then offers conclusions about the literature as well as suggestions for future research. The last section highlights the key and most critical issue around the angel investment literature - the lack of generalizable data and a dearth of strong methods. Each section provides a set of summary tables to aid the reader. These tables include every article reviewed in that section, the bibliographic data, main research question, theoretical perspective if applicable, and a summary of the findings.