Marco Giallini (born 4 April 1963) is an Italian actor.
Born in Rome, Giallini is the son of a housewife and a furnace labourer. After attending the Accademia Nazionale di Arte Drammatica Silvio D'Amico, he began acting on stage, working among others with Arnoldo Foà and Angelo Orlando. He made his film debut in 1995, in the Orlando's comedy film L'anno prossimo vado a letto alle dieci. He appeared on several TV-series and was co-protagonist, alongside Valerio Mastandrea, of the Rai Tre sitcom Buttafuori. He is also very active in music videos and short films.
In 2012 Giallini won the Nastro d'Argento for best supporting actor thanks to his performance in ACAB - All Cops Are Bastards. The same year he won the Ciak d'oro as personality of the year.
Giallini was married to his wife Loredana for 25 years, and they had two children. He has remained a widower since July 2011, when his wife was struck down by a cerebral hemorrhage.