Tedesco returns as Australia's fullback and captain against Fiji in Sunday's World Cup match at Suncorp Stadium.
Fifita, Walker, Brailey and Best will all make their Kangaroos debuts.
Fifita, 26, played four Tests for Tonga at the 2022 World Cup.
His move from Gold Coast to South Sydney under Wayne Bennett this year restored his NRL form.
Earlier this month, he captained the Prime Minister's XIII to a 60-10 victory over PNG. He will start alongside North Queensland co-captain Reuben Cotter.
Walker makes his first Australian start after a Sydney Roosters premiership and a Queensland State of Origin debut.
Mitchell Moses' leg injury during Australia's 24-22 win over New Zealand last week gives Walker a chance to claim the No. 7 spot.
Brailey and Best were key figures in New South Wales' 2-1 Origin series win.
Regular captain Isaah Yeo is rested, while Reece Walsh is listed at No. 18 on the extended bench.
Keaon Koloamatangi and Lindsay Smith start in the front row, with Cameron Murray moving to No. 13 after coming off the bench against New Zealand.