Both riders are former overall winners of the race, with Thomas having claimed the victory in 2015 and 2016 and Kwiatkowski in 2014, when he was riding for Omega Pharma-Quick Step.
The pair will be joined by Owain Doull, Kenny Elissonde, Michal Golas, Vasil Kiryienka and Lukasz Wisniowski in Sky’s seven-rider line-up, which will see Thomas’s 2018 competitive debut.
Primož Roglič (LottoNL-Jumbo) claimed the overall victory in last year’s edition of the race, with Kwiatkowski placing second.
The 2018 Volta ao Algarve comprises five stages, with stage two’s summit finish at Fóia, stage five’s finale on Alto do Malhão and stage three’s 20.3km individual time trial the significant factors in settling the general classification.
Meanwhile, Sky has also confirmed the list of rider accompanying Chris Froome at his season debut in the Ruta del Sol in Spain over February 14-18.
Froome is joined by a strong team consisting of David de la Cruz, Philip Deignan, Chris Froome, Christian Knees, Wout Poels, Salvatore Puccio and Dylan van Baarle.
The hilly race will be decided by the final day’s individual time trial, comprising 14.2 flat kilometres.
Froome is currently waiting to hear the decision on his adverse analytical finding for salbutamol at the 2017 Vuelta a España. He is currently clear to race, and is forging ahead with preparations to ride the Giro d’Italia in May.