A fastening device for fastening at least one sensor to a railway rail includes at least one clamping bow and at least two mutually opposite clamping regions connected to the clamping bow. The at least one sensor and at least part of the railway rail can be disposed between the clamping regions. At least one clamping device is connected to the clamping bow for applying the clamping force between the clamping regions for fastening the at least one sensor to the railway rail. A sensor arrangement including the fastening device and a method for fastening at least one sensor to a railway rail are also provided.