A novel cotton cultivar, designated DP 494 RR, is disclosed. The invention relates to the seeds of cotton cultivar DP 494 RR, to the plants of cotton DP 494 RR and to methods for producing a cotton plant produced by crossing the cultivar DP 494 RR with itself or another cotton variety. The invention further relates to hybrid cotton seeds and plants produced by crossing the cultivar DP 494 RR with another cotton cultivar.