Joonas is an Estonian^[1] and Finnish given name, a cognate of Jonas. Notable people with the given name include:

• Joonas Alanne (born 1990), Finnish ice hockey player
• Joonas Angeria (born 1989), Finnish music producer, songwriter and musician
• Joonas Cavén (born 1993), Finnish basketball player
• Joonas Donskoi (born 1992), Finnish ice hockey player
• Joonas Granberg (born 1986), Finnish golfer
• Joonas Hallikainen (born 1985), Finnish ice hockey player
• Joonas Henttala (born 1991), Finnish racing cyclist
• Joonas Hurri (born 1991), Finnish ice hockey player
• Joonas Iisalo (born 1986), Finnish basketball coach and former player
• Joonas Ikäläinen (born 1982), Finnish footballer
• Joonas Jääskeläinen (born 1973), Finnish ice hockey player
• Joonas Jalvanti (born 1988), Finnish ice hockey player
• Joonas Järveläinen (born 1990), Estonian basketball player
• Joonas Järvinen (born 1989), Finnish ice hockey player
• Joonas Kemppainen (born 1988), Finnish ice hockey player
• Joonas Kokkonen (1921–1996), Finnish composer
• Joonas Kolkka (born 1974), Finnish footballer
• Joonas Komulainen (born 1990), Finnish ice hockey player
• Joonas Korpisalo (born 1994), Finnish ice hockey player
• Joonas Koskinen (born 1987), Finnish ice hockey player
• Joonas Kuusela (born 1990), Finnish ice hockey player
• Joonas Kylmäkorpi (born 1980), Finnish motorcycle speedway rider
• Joonas Laurikainen (born 1983), Finnish footballer
• Joonas Lehtivuori (born 1988), Finnish ice hockey player
• Joonas Liimatainen (born 1991), Finnish ice hockey player
• Joonas Lindgren (born 1986), Finnish sailor and Olympic competitor
• Joonas Myyrä (1892–1955), Finnish javelin thrower
• Joonas Nättinen (born 1991), Finnish ice hockey player
• Joonas Pöntinen (born 1990), Finnish footballer
• Joonas Rask (born 1990), Finnish ice hockey player
• Joonas Riekkinen (born 1987), Finnish ice hockey player
• Joonas Riismaa (born 2002), Estonian basketball player
• Joonas Ronnberg (born 1983), Finnish ice hockey player
• Joonas Sammalmaa (born 1991), Finnish ice hockey player
• Joonas Sarelius (born 1979), Finnish footballer
• Joonas Sildre (born 1980), Estonian comics artist, illustrator and graphic designer
• Joonas Suotamo (born 1986), Finnish actor and former basketball player
• Joonas Tamm (born 1992), Estonian footballer
• Joonas Toivanen (born 1991), Finnish ice hockey player
• Joonas Vaino (born 1992), Estonian basketball player
• Joonas Valkonen (born 1993), Finnish ice hockey player
• Joonas Vihko (born 1981), Finnish ice hockey player

As a surname

• Velly Joonas (born 1955), Estonian musician, songwriter and poet