Here is the full list of all 51 Red Dead Redemption 2 achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Earn 70 Gold Medals in Story missions.
Attain 100% completion.
Skin every species of animal in Story Mode.
Study every animal across all states in Story Mode.
Survive 18 bear attacks and kill the bear each time in Story Mode.
Craft 30 unique items in Story Mode.
Find a permanent home for the squirrel statue.
Complete one of the Collectable strands.
Complete 10 Stranger mission strands.
Find the graves of each of your fallen companions.
Survive 3 days holding a bounty of $250 in all states.
Discover the fate of Marko Dragic.
Spend $5000 across all shops.
Complete the Epilogue.
Complete 'A New Jerusalem'.
Complete 'Red Dead Redemption'.
Complete all optional Honor story missions.
Reach maximum or minimum Honor level.
Complete 'Goodbye, Dear Friend'.
Complete Chapter 5.
Complete Chapter 4.
Rob or loot $250.
Complete a Companion Activity in each camp.
Play all mini games.
Complete Chapter 3.
Red Dead Online: Achieve MVP 3 times (in a round with at least 4 players).
Deliver 5 camp companion item requests.
Complete Chapter 2.
Upgrade each available component for a single sidearm or longarm weapon.
Red Dead Online: Concurrently own 5 horses.
Donate $250 to the gang tithing box.
Recover the stash from 4 homesteads.
Complete Chapter 1.
Catch a fish weighing at least 16 lbs (7.3 kg).
Red Dead Online: Craft 25 pieces of ammunition.
Red Dead Online: Successfully counter a rival Posse's Free Roam mission.
Red Dead Online: Purchase 5 camp improvements.
Red Dead Online: Play 5 Free Roam Events.
Red Dead Online: Craft 20 items (excluding ammo).
Red Dead Online: Reach Rank 50.
Red Dead Online: Form a Persistent Posse.
Reach max bonding level with a horse.
Red Dead Online: Achieve 5 gold belt buckles from awards.
Red Dead Online: Sell 20 items to the Butcher.
Red Dead Online: Pick 25 Herbs.
Red Dead Online: Take part in a Series.
Red Dead Online: Accept 10 Free Roam missions from characters around the world.
Red Dead Online: Reach Rank 10.
Red Dead Online: Complete a Free Roam mission as part of a Posse with at least 2 members.
Red Dead Online: Complete the Intro.
Complete 'Enter, Pursued by a Memory'.