In　recent　years,　the　measurement　of　dam　displacements　has　benefited　from　a　great　improvement　of　existing　technology,　which　has　allowed　a　higher　degree　of　automation.　This　has　led　to　data　collection　with　an　improved　temporal　and　spatial　resolution.　Robotic　total　stations　and　GNSS　(Global　Navigation　Satellite　System)　techniques,　often　in　an　integrated　manner,　may　provide　efficient　solutions　for　measuring　3D　displacements　on　precise　locations　on　the　outer　surfaces　of　dams.　On　the　other　hand,　remote-sensing　techniques,　such　as　terrestrial　laser　scanning,　ground-based　SAR　(synthetic　aperture　radar)　and　satellite　differential　interferometric　SAR　offer　the　chance　to　extend　the　observed　region　to　a　large　portion　of　a　structure　and　its　surrounding　areas,　integrating　the　information　that　is　usually　provided　in　a　limited　number　of　in-situ　control　points.　The　design　and　implementation　of　integrated　monitoring　systems　have　been　revealed　as　a　strategic　solution　to　analyze　different　situations　in　a　spatial　and　temporal　context.　Research　devoted　to　the　optimization　of　data　processing　tools　has　evolved　with　the　aim　of　improving　the　accuracy　and　reliability　of　the　measured　deformations.　The　analysis　of　the　observed　data　for　the　interpretation　and　prediction　of　dam　deformations　under　external　loads　has　been　largely　investigated　on　the　basis　of　purely　statistical　or　deterministic　methods.　The　latter　may　integrate　observation　from　geodetic,　remote-sensing　and　geotechnical/structural　sensors　with　mechanical　models　of　the　dam　structure.　In　this　paper,　a　review　of　the　available　technologies　for　dam　deformation　monitoring　is　provided,　including　those　sensors　that　are　already　applied　in　routinary　operations　and　some　experimental　solutions.　The　aim　was　to　support　people　who　are　working　in　this　field　to　have　a　complete　view　of　existing　solutions,　as　well　as　to　understand　future　directions　and　trends.