Lahti is a Finnish surname of Laine type meaning "bay" or "gulf".
Aimo Lahti (1896–1970), Finnish weapon designer
Aki Lahti (1931–1998), Finnish chess master
Arto Lahti (born 1949), Finnish professor and politician
Christine Lahti (born 1950), American actress
Jeff Lahti (born 1956), American baseball player
Jenny Lahti Velsek (1913–2006), American labor activist
Marielle Lahti (born 1969), Swedish politician
Michael Lahti (1945–2025), American politician (Michigan)
Reinhold Lahti (1930–2002), Swedish Army major general
Timi Lahti (born 1990), Finnish footballer