The pair had each been substituted in the defeat to Cameroon, with team doctor Rodrigo Lasmar confirming afterwards they would have scans the next day.
Brazil has already been playing without Neymar, Danilo and Alex Sandro due to injuries, and these latest two setbacks are significant.
Reports in Brazil had suggested Jesus would miss a month and Telles was potentially facing surgery, also representing blows to Arsenal and Sevilla.
A statement from the CBF subsequently confirmed neither would feature for the remainder of the World Cup.
"As announced by the CBF after the game against Cameroon, players Alex Telles and Gabriel Jesus underwent tests this Saturday morning," the statement read.
"Accompanied by the doctor of the Brazilian team, Rodrigo Lasmar, they performed an MRI on the right knee that confirmed the injuries and the impossibility of recovery in time to participate in the FIFA World Cup Qatar 2022.
"The coordinator of the Brazilian national team, Juninho Paulista, is in contact with the sports directors of Arsenal and Sevilla to define whether Alex Telles and Gabriel Jesus remain with the squad in Doha for continuity of treatment or if they return to their clubs."
While Jesus was set to play only as Richarlison's back-up in the knockout stage, Telles could have been in line for a prominent role.
Alex Sandro is the only other natural left-back in the squad and is uncertain to return in time for the last-16 match against South Korea.
Brazil is at least more optimistic on the status of versatile right-back Danilo, who was set to return to full training on Sunday (AEDT).