The most prevalent form of malignant tumor in females is breast cancer. For women worldwide, it is the leading cause of cancer-related death. Despite the large body of knowledge on the detection and management of breast cancer, patient morbidity and death rates are still very high. Chemotherapy is extensively used treatment for advanced breast cancer; it can be administered intravenously or orally and is often coupled with other therapeutic modalities such radiotherapy, surgery, and heat. Due to several limitations doctors favour the cutaneous injection approach. However, patients’ concerns about injection discomfort, needle pollution in the environment, and the requirement for recurrent, periodic injections pose challenges to subcutaneous or intravenous injections. The use of microneedles in cancer treatments is also being thoroughly researched since they offer a more effective treatment method through self-administration, painless therapy, as well as an economical and ecologically friendly approach when compared to other traditional methods. A great chance for safer and more effective medications that could meet the needs of cancer detection and treatment in a range of settings is offered by the development of advanced transdermal drug delivery systems. This chapter emphasises the types of microneedles, materials used and techniques applied for fabrication of microneedles. Along with this, therapeutic and diagnostic microneedles for breast cancer are also included. In addition, this chapter also mentions on-going as well as completed clinical trials and regulations of microneedle patches.