Justinas is a masculine Lithuanian given name, equivalent to Justin. Notable people with the name include:

• Justinas Beržanskis (born 1989), Lithuanian steeplechase runner
• Justinas Januševskij (born 1994), Lithuanian footballer
• Justinas Kinderis (born 1987), Lithuanian modern pentathlete
• Justinas Lagunavičius (1924–1997), Lithuanian basketball player
• Justinas Marazas (born 2000), Lithuanian footballer
• Justinas Marcinkevičius (1930–2011), Lithuanian poet and playwright
• Justinas Pranaitis (1861–1917), Lithuanian Catholic priest
• Justinas Staugaitis (1866–1943), Lithuanian Roman Catholic bishop, politician, educator and writer
• Justinas Usonis (born 1975), Lithuanian lawyer and legal scholar