Fakhar Zaman of Pakistan is the quickest to reach 1000 runs in One Day International Cricket.He reached 1000 runs in 18 innings.
Innings (for 1000 runs) Batsman
18 Fakhar Zaman
21 Viv Richards, Kevin Pietersen, Jonathan Trott, Quinton de Kock, Babar Azam
22 Gordon Greenidge, Ryan ten Doeschate, Azhar ali