There has been published the special issue of the journal Soft Computing dedicated to the 3rd international conference ‘‘Numerical Computations: Theory and Algorithms-NUMTA 2019’’, June 15-21, 2019, Isola Capo Rizzuto, Italy. The special issue contains 23 papers. It has been edited by Yaroslav D. Sergeyev (Managing Guest-Editor) and Renato De Leone and Gerardo Toraldo (Guest-Editors).