There are a total of 86 fighters on the completed Super Smash Bros. Ultimate roster with the addition of Sora

Nintendo has confirmed a total of 86 confirmed playable characters in Super Smash Bros. Ultimate, from Mario to the recently-revealed Sora:

1. Mario
2. Donkey Kong
3. Link
4. Samus
5. Dark Samus
6. Yoshi
7. Kirby
8. Fox
9. Pikachu
10. Luigi
11. Ness
12. Captain Falcon
13. Jigglypuff
14. Peach
15. Daisy
16. Bowser
17. Ice Climbers
18. Sheik
19. Zelda
20. Dr. Mario
21. Pichu
22. Falco
23. Marth
24. Lucina
25. Young Link
26. Ganondorf
27. Mewtwo
28. Roy
29. Chrom
30. Mr. Game & Watch
31. Meta Knight
32. Pit
33. Dark Pit
34. Zero Suit Samus
35. Wario
36. Snake
37. Ike
38. Pokémon Trainer: Squirtle
39. Pokémon Trainer: Ivysaur
40. Pokémon Trainer: Charizard
41. Diddy Kong
42. Lucas
43. Sonic
44. King Dedede
45. Olimar
46. Lucario
47. R.O.B.
48. Toon Link
49. Wolf
50. Villager
51. Mega Man
52. Wii Fit Trainer
53. Rosalina & Luma
54. Little Mac
55. Greninja
56. Mii Fighter: Brawler
57. Mii Fighter: Swordfighter
58. Mii Fighter: Gunner
59. Palutena
60. Pac-Man
61. Robin
62. Shulk
63. Bowser Jr.
64. Duck Hunt
65. Ryu, Ken
66. Cloud
67. Corrin
68. Bayonetta
69. Inkling
70. Ridley
71. Simon, Richter
72. King K. Rool
73. Isabelle
74. Incineroar
75. Piranha Plant
76. Joker
77. Hero
78. Banjo & Kazooie
79. Terry
80. Byleth
81. Min Min
82. Steve
83. Sephiroth
84. Pyra/Mythra
85. Kazuya
86. Sora

Source: smashbros.com

Source: Pokemon