Abstract: Multi-messenger astronomy enables us to probe extreme astrophysical phenomena in new ways. In particular, astrophysical neutrinos reveal information that is not available via any other messenger. Neutrinos are the “smoking gun” signature for hadronic processes – meaning that identification of neutrino sources can elucidate the origins of high-energy cosmic rays. Multiple observatories, such as the IceCube Neutrino Observatory and KM3NeT, are currently collecting data on astrophysical neutrinos. The first detection of high-energy astrophysical neutrinos was reported in 2013 by the IceCube collaboration. However, despite detecting astrophysical neutrinos for over a decade, the sources of these neutrinos are still largely unknown, despite thorough searches. I will present results and work in progress from three such searches using data from the IceCube Neutrino Observatory. The first is a search for neutrinos from SN 2023ixf, the closest and brightest core-collapse supernova in the last decade. The second is a follow-up of the highest-energy neutrino ever detected, measured by KM3NeT to have energy approximately 200 PeV, to search for additional neutrinos from the same direction that could help determine its origin. Finally, I will present a search under development for neutrinos in the directions of fast radio bursts (FRBs) detected by the CHIME telescope.