LEO satellites are to be equipped with mMIMO in the near future. Introducing the beam-based positioning paradigm marks the advent of a new research topic that is concerned with exploiting 5G beamforming features of LEO satellites’ communications to infer UT position in Earth’s coordinates. Considering the passive SoO nature of the proposed method, the simulation results (MAE = 0.22 km with 100 satellites) are considered very promising, as positioning is possible even in poor GDOP situations. Furthermore, the proposed method does not require high-accuracy measurements at the receiver side, thus reducing costs and sensitivity to interference. As future work, more sophisticated simulation environment will be built to model mMIMO beamforming components, the communication channel, and various sources of noise and interference. In addition, LEO satellite orbits and realistic mega constellations will be modelled. Additional positioning algorithms will be developed and analyzed for enhanced accuracy and reliability. The proposed ideas within this article are currently under the process of IPR patenting (Finnish patent application number: 20235545).