Leonardoi Pizani (Leonardo Pisano), yo khud Fibonachi (Fibonacci) (taqriban soli 1170 tavallud shuda badi soli 1228 vafot kardaast), matematiki italiyavi. Ba mamlakathoi Sharq, safar karda, bo komyobihoi matematikai arab shinos shudaast; in baroi dar mamlakathoi Garb pahn shudani matematikai Sharq kumak rasond.
Asarhoi asosiash «Liher Abaci» (1202)—risola dar borai arifmetika (raqamhoi hindi, adadhoi Fibonachchi) va algebra (to khudi muodilahoi kvadrati), «Practica Geo-metriae» (1220) avvalin asarhoeand, ki tatbiqi masalahoi algebraro dar geometriya dar bar giriftaand.