Sha'Carri Richardson seems to be bitter about the heat she's gotten after coming in dead last over the weekend -- at least, according to her Twitter account ... which just "liked" an offensive tweet about Jamaicans.
The 21-year-old track star competed in the Prefontaine Classic in Oregon on Saturday ... losing to the 3 Jamaican runners who won gold, silver and bronze at the 2020 Olympics.
Richardson -- who finished with a time of 11.14 seconds -- brushed off the L and welcomed any haters to "talk all the s*** you want to" .