Political ideology is generally seen to be very outspoken. Animated debates are considered the core of democratic decision making. While a lot of isms, such as liberalism, conservatism, socialism, and creationism, form part of the political debate, values and ideology in public service delivery are often not acknowledged or scrutinized. Public services are often presented as a matter of neutral implementation. We argue in this chapter that public services are far from ideology free. Key to our argument is that ideologies can be loud or silent and that silent ideologies in public service delivery do not get enough attention. Since they nonetheless have an effect on public service performance, it is important to expose those silent ideologies. This chapter studies three silent ideologies in fields for which we had case evidence available: frontline professionalism, technology, and citizen participation.