Landfill reclamation is a complex process. It requires long-term monitoring of multiple, ever-changing environmental factors such as leachate, migration of pollutants to water, biogas and atmospheric emissions, as well as geotechnical factors such as stability and subsidence. Remote sensing methods, having the ability to collect data over a large area and with high spatial and temporal resolution, can be particularly useful in monitoring these factors. Periodic monitoring makes it possible to detect even the smallest changes occurring in a landfill and to assess the effectiveness of remediation. Monitoring data also allows the detection of damage to the landfill body caused by subsidence, surface water run-off caused by heavy rainfall, and wild animal activity. This helps to detect and repair potential problems before they become major hazards. Particularly useful in remote sensing methods is the use of Unmanned Aerial Vehicles (UAV), which, together with appropriate sensors, allow detailed data to be provided in a short time and at high frequency. The use of UAVs in this type of measurement offers an interesting and much cheaper alternative to aerial and satellite data. To present the possibilities of using remote sensing data, a case study of the Słabomierz-Krzyżówka landfill site is presented. The landfill has been already closed and its future development is intended for a photovoltaic farm. The reclaimed landfill covers an area of 13 ha and has a height of 30 m. The survey used an RGB camera, a multispectral camera, a thermal camera, and a laser scanner. These sensors, combined with the UAV, allowed the landfill to be inventoried and to identify changes such as damage to the landfill’s mineral cover. The collected data also made it possible to detect changes in the vegetation cover of the landfill caused by the impact of outflowing pollutants. Vegetation can be used as a bio-indicator for potential sites of pollution outflow from the landfill.