The acceleration of ions using laser-based techniques has attracted very significant interest in the scientific community over the last two decades. Beams accelerated through these techniques have unique properties, particularly in terms of their ultrashort temporal profile, which are very distinctive and different from the characteristics of beams obtained from conventional accelerators. This is driving their use in innovative scientific applications which are currently being pursued in the major high-power laser laboratories worldwide. These range from applications in advanced radiography techniques to the production and characterization of exotic states of matter. The prospect for future clinical application is also a strong motivation for research in the acceleration of protons and heavier ions. In particular, the ultrashort nature of the ion pulses makes their application in in-vitro and in-vivo radiobiology particularly interesting, in light of the current interest in FLASH irradiations at very high dose rates. The lectures will review the state-of-the-art and recent progress in the laser acceleration of ions, discussing the main acceleration mechanisms, including the well-established Target Normal Sheath Acceleration process, but also emerging processes, including those aiming to harness the strong Radiation Pressure of an intense laser pulse, and the field enhancement associated to regimes of relativistic transparency of an expanded foil. Recent advances in applicative usage of laser-accelerated protons and carbons will also be discussed, as well as perspectives for future developments in the multi-Petawatt regime.