I created a list of (published-only) races, classes, and backgrouds:
Races & Subraces
AARAKOCRA [EEPC]
AASIMAR
Fallen Aasimar [VGtM]
Protector Aasimar [VGtM]
Scourge Aasimar [VGtM]
BUGBEAR [VGTM]
DRAGONBORN [PHB]
DWARF
Gray Dwarves (Duergar) [SCAG]
Hill Dwarf [PHB]
Mountain Dwarf [PHB]
ELF
Dark Elf (Drow) [PHB]
High Elf [PHB]
Wood Elf [PHB]
FIRBOLG [VGTM]
GENASI
Air Genasi [PotA, EEPC]
Earth Genasi [PotA, EEPC]
Fire Genasi [PotA, EEPC]
Water Genasi [PotA, EEPC]
GNOME
Deep Gnome (Svirfneblin) [EEPC, SCAG]
Forest Gnome [PHB]
Rock Gnome [PHB]
GOBLIN [VGTM]
GOLIATH [EEPC, VGTM]
HALF-ELF [PHB]
Half-Elf Variants [SCAG]
HALF-ORC [PHB]
HALFLING
Lightfoot [PHB]
Stout [PHB]
HOBGOBLIN [VGTM]
HUMAN [PHB]
KENKU [VGTM]
KOBOLD [VGTM]
LIZARDFOLK [VGTM]
ORC [VGTM]
TABAXI [VGTM]
TRITON [VGTM]
TIEFLING [PHB]
Tiefling Variants [SCAG]
YUAN-TI PUREBLOOD [VGTM]
Classes & Subclasses
BARBARIAN
Path of the Ancestral Guardian [XGtE]
Path of the Battlerager [SCAG]
Path of the Beserker [PHB]
Path of the Storm Herald [XGtE]
Path of the Totem Warrior [PHB, SCAG]
Path of the Zealot [XGtE]
BARD
College of Glamour [XGtE]
College of Lore [PHB]
College of Swords [XGtE]
College of Valor [PHB]
College of Whispers [XGtE]
CLERIC
Arcana Domain [SCAG]
Death Domain [DMG]
Forge Domain [XGtE]
Grave Domain [XGtE]
Knowledge Domain [PHB]
Life Domain [PHB]
Light Domain [PHB]
Nature Domain [PHB]
Tempest Domain [PHB]
Trickery Domain [PHB]
War Domain [PHB]
DRUID
Circle of Dreams [XGtE]
Circle of the Land [PHB]
Circle of the Moon [PHB]
Circle of the Shepherd [XGtE]
FIGHTER
Arcane Archer [XGtE]
Battle Master [PHB]
Cavalier [XGtE]
Champion [PHB]
Eldritch Knight [PHB]
Purple Dragon Knight (Banneret) [SCAG]
Samurai [XGtE]
MONK
Way of the Drunken Master [XGtE]
Way of the Four Elements [PHB]
Way of the Kensei [XGtE]
Way of the Long Death [SCAG]
Way of the Open Hand [PHB]
Way of Shadow [PHB]
Way of the Sun Soul [SCAG, XGtE]
PALADIN
Oath of the Ancients [PHB]
Oath of Conquest [XGtE]
Oath of the Crown [SCAG]
Oath of Devotion [PHB]
Oath of the Oathbreaker [DMG]
Oath of Redemption [XGtE]
Oath of Vengeance [PHB]
RANGER
Beast Master [PHB]
Gloom Stalker [XGtE]
Horizon Walker [XGtE]
Hunter [PHB]
Monster Slayer [XGtE]
ROGUE
Arcane Trickster [PHB]
Assassin [PHB]
Inquisitive [XGtE]
Mastermind [SCAG, XGtE]
Scout [XGtE]
Swashbuckler [SCAG, XGtE]
Thief [PHB]
SORCERER
Divine Soul [XGtE]
Draconic Bloodline [PHB]
Shadow Magic [XGtE]
Storm Sorcery [SCAG, XGtE]
Wild Magic [PHB]
WARLOCK
Pact of the Archfey [PHB]
Pact of the Celestial [XGtE]
Pact of the Fiend [PHB]
Pact of the Great Old One [PHB]
Pact of the Hexblade [XGtE]
Pact of the Undying [SCAG]
WIZARD
Bladesinging [SCAG]
School of Abjuration [PHB]
School of Conjuration [PHB]
School of Divination [PHB]
School of Enchantment [PHB]
School of Evocation [PHB]
School of Illusion [PHB]
School of Necromancy [PHB]
School of Trasmutation [PHB]
War Magic [XGtE]
Backgrounds
ACOLYTE [PHB]
ANTHROPOLOGIST [TOA]
ARCHAEOLOGIST [TOA]
CHARLATAN [PHB]
CITY WATCH [SCAG]
Variant: Investigator [SCAG]
CLAN CRAFTER [SCAG]
CLOISTERED SCHOLAR [SCAG]
COURTIER [SCAG]
CRIMINAL [PHB]
Variant Criminal: Spy [PHB]
ENTERTAINER [PHB]
Variant Entertainer: Gladiator [PHB]
FACTION AGENT [SCAG]
FAR TRAVELER [SCAG]
FOLK HERO [PHB]
GUILD ARTISAN [PHB]
Variant Guild Artisan: Guild Merchant [PHB]
HAUNTED ONE [COS]
HERMIT [PHB]
INHERITOR [SCAG]
KNIGHT OF THE ORDER [SCAG]
MERCENARY VETERAN [SCAG]
NOBLE [PHB]
Variant Noble: Knight [PHB]
OUTLANDER [PHB]
SAGE [PHB]
SAILOR [PHB]
Variant Sailor: Pirate [PHB]
SOLDIER [PHB]
URBAN BOUNTY HUNTER [SCAG]
URCHIN [PHB]
UTHGARDT TRIBE MEMBER [SCAG]
WATERDHAVIAN NOBLE [SCAG]
SUBSTITUTE FEATURES
Optional Feature: Cult of the Dragon Infiltrator [HotDQ]
Optional Feature: Deep Delver [OotA]
Optional Feature: Dragon Scholar [HotDQ]
Optional Feature: Underdark Experience [OotA]
SUBSTITUTE BONDS [HOTDQ, OOTA]
