Ceramic membranes find widespread applications in industrial and municipal wastewater treatment owing to their high mechanical strength and chemical stability that make them suitable to treat a wide range of effluents. Capital cost of the ceramic membranes made from relatively expensive metal oxides, being a major limitation, development of cost-effective ceramic membranes is addressed using various alternative raw materials that are cheap and abundant, such as fly ash, ball clay and kaolin; and employing low sintering temperatures (<1000 °C). There has been a tremendous amount of research carried out in the past two decades on the fabrication of low-cost ceramic membranes for micro- and ultrafiltration applications. This chapter discusses various aspects of preparation, characterization, and applications of low-cost membranes based on fly ash and kaolin, with an emphasis on the role of the raw materials and inorganic pore formers.