Johannes Wilhelm "Hans" Geiger (; Jamus: [ˈɡaɪɡɐ]; 30 Satumba 1882 <unk> 24 Satumba 1945) wani masanin kimiyyar lissafi ne na Jamus. An fi saninsa da haɗin gwiwar mai gano kayan aikin Geiger da kuma gwajin Geiger <unk> Marsden wanda ya gano kwayar zarra. Shi ɗan'uwan masanin yanayi ne kuma masanin yanayi Rudolf Geiger. Tambaya: Wanene ya gano kwayar atomatik.
Johannes Wilhelm "Hans" Geiger