Wallentin is a Swedish surname. Notable people with the surname include:
Folke Ronnie Wallentin Hellström (1949–2022), Swedish professional footballer Gabriel Wallentin (born 2001), Swedish footballer Jan Wallentin (born 1970), Swedish journalist and writer Lars Wallentin (born 1943), Swedish physician and cardiologist Mariam Wallentin (born 1982), Swedish musician and voice actress Tassilo Wallentin (born 1973), Austrian author, columnist, and lawyer Uno Wallentin (1905–1954), Swedish sailor