List going by Paldea Pokedex:I did some thinking. And I realized that Gholdengo would be the actual 1,000th Pokemon in the Pokedex.
906. Sprigatito
907. Floragato
908. Meowscarada
909. Fuecoco
910. Crocalor
911. Skeledirge
912. Quaxly
913. Quaxwell
914. Quaquaval
915. Lechonk
916. Oinkologne
917. Tarountula
918. Spidops
919. Nymble
920. Lokix
921. Pawmi
922. Pawmo
923. Pawmot
924. Clodsire
925. Tandemaus
926. Maushold
927. Fidough
928. Dachsbun
929. Smoliv
930. Dolliv
931. Arboliva
932. Squakabilly
933. Nacli
934. Naclstack
935. Garganacl
936. Annihilape
937. Charcadet
938. Armarouge
939. Ceruledge
940. Tadbulb
941. Bellibolt
942. Wattrel
943. Kilowattrel
944. Dudunsparce
945. Farigiraf
946. Maschiff
947. Mabosstiff
948. Shroodle
949. Grafaiai
950. Bramblin
951. Brambleghast
952. Toedscool
953. Toedscruel
954. Klawf
955. Capsakid
956. Scovillain
957. Rellor
958. Rabsca
959. Flittle
960. Espathra
961. Tinkatink
962. Tinkatuff
963. Tinkaton
964. Wiglett
965. Wugtrio
966. Bombirdier
967. Finizen
968. Palafin
969. Varoom
970. Revaroom
971. Cyclizar
972. Orthworm
973. Glimmet
974. Glimmora
975. Greavard
976. Houndstone
977. Flamigo
978. Cetoddle
979. Cetitan
980. Kingambit
981. Veluza
982. Dondozo
983. Tatsugiri
984. Great Tusk
985. Scream Tail
986. Brute Bonnet
987. Flutter Mane
988. Slither Wing
989. Sandy Shocks
990. Iron Treads
991. Iron Bundle
992. Iron Hands
993. Iron Jugulis
994. Iron Moth
995. Iron Thorns
996. Frigibax
997. Arctibax
998. Baxcalibur
999. Gimmighoul
1000. Gholdenga
1001. Wo-Chien
1002. Chien-Pao
1003. Ting-Lu
1004. Chi-Yu
1005. Roaring Moon
1006. Iron Valiant
1007. Koraidon
1008. Miraidon