This dissertation explores how younger-generation Malay Muslims in Malaysia enact Islamic piety through ethical practices of economic action in entrepreneurial business and finance. I look to key sites in urban Malaysia where Malay Muslims develop their understandings and practices of piety as economic action, and vice versa - in the fields of technology startup enterprise, venture capital, Islamic banking and finance, and in forms of consumer debt such as credit cards, personal loans, and home mortgages - in order to trace how they have emerged as ethical issues, and what kinds of grapplings they have engendered. The expansion of these economic sectors, loosely aggregated under the label of entrepreneurship and finance in Malaysia, represent comprehensive efforts by the Malaysian state to increase national wealth and re-allocate capital from the hands of historically affluent groups of ethnic minorities, such as the Chinese, to the hands of the nation's ethno-religious majority group, Malay Muslims. After more than 150 years of British colonial rule that ended in 1957, a newly independent Malaysia, led by pro-Malay Muslim political figures, was left struggling to come to terms with the economic disparity that resulted from colonial governance policies tying race to labor. The unevenness of this capital accumulation has created the conditions in which Islamic understandings of proper conduct in exchange and finance have come to be positioned in opposition with conventional (that is, non-Islamic) modes of commerce. I argue that Malay Muslims' understanding of economic action as ethical - and therefore as political - developed within these historical conditions as a result of their participation in social spaces such as Islamic study circles, where they are encouraged by scholars (and by one another) to reflect upon, evaluate, and make changes to the way that they engage with dominant forms of contemporary capitalism. Put into practice, these understandings and explorations of ethics in economic action have developed into projects of critique, reform, and intervention into the normative and taken-for-granted ways that capitalism is assumed to operate in their daily lives as entrepreneurs and financiers - as profit maximization, calculative logic, and interest. By dis-embedding the assumption in theories of economy that individuals maximize toward their own interests, these interventions make possible another economics grounded in Islamic ethics. Furthermore, I examine how the ability of today's younger-generation pious Muslims to critique and re-imagine the operations of capitalism in this manner - through articulations of its limitations, injustice, and oppression - is enabled by their familiarity with its normative forms, having come of age in a "financialized" Malaysia characterized by the primacy of investment logics and entrepreneurial merit. While younger-generation, middle-class Malay Muslims are critical of the neoliberal economic reforms initiated by the Malaysian state (as well as the growth of the financial and business sectors that resulted from these reforms), these critiques are often forged and articulated through pious practices of ethical self-cultivation that resonate with what some might call a form of neoliberal self-governance. But rather than assume that pious Muslims are therefore figures of "neoliberal piety" whose ethical attachments and practices remain epiphenomenal to their economic subjectivity, I hold this tension between the object of their critique and the mode of their critique, theorizing that it is hegemonic capitalism itself that contains within it these tools of critique, thereby making it possible to imagine and take action toward living a life outside of neoliberal capitalism. This dissertation therefore makes a key intervention within the study of Islamic piety by examining how, in its concentration on ethical economic practices, pious self-cultivation can be oriented toward not only affecting change within the self, but also toward eliciting ethical transformation within broader Muslim society.