Uhusianifu maalumu (kwa Kiingereza: special relativity) ni nadharia iliyoundwa na Albert Einstein mwaka 1905. Nadharia hiyo husema: Wachunguzi wakiwa na mwendo tofauti, hukuona wakati na umbali hubadilishwa, katika fomula γ=(1-v2/c2)-1/2. Inayolingana nishati na tungamo katika fomula E=mc2. Kasi ya nuru huwa sawa kwa wachunguzi wote. Majaribio mengi yamethibitisha nadharia hiyo na ile ya uhusianifu wa jumla, kama vile majaribio wa Michelson-Morley na majaribio wa Ives-Stilwell (nadharia ya uhusianifu maalum), na majaribio wa Pound-Rebka (nadharia ya uhusianifu wa jumla). http://www.edu-observatory.org/physics-faq/Relativity/SR/experiments.html Einstein, Albert (1920). Relativity: The Special and General Theory. Einstein, Albert (1996). The Meaning of Relativity. Fine Communications. Kigezo:Isbn Logunov, Anatoly A. (2005) Henri Poincaré and the Relativity Theory (transl. from Russian by G. Pontocorvo and V. O. Soleviev, edited by V. A. Petrov) Nauka, Moscow. Charles Misner, Kip Thorne, and John Archibald Wheeler (1971) Gravitation. W. H. Freeman & Co. Kigezo:Isbn Post, E.J., 1997 (1962) Formal Structure of Electromagnetics: General Covariance and Electromagnetics.