Sadly the rules on curing disease do not seem to be organized in a single section of any of the rule books. Here are all the options I can find:
Lesser Restoration (2nd level) can end 1 disease afflicting the target
Raise Dead (5th level, 500gp consumed material component) cures non-magical diseases that afflicted the deceased at the time of its death.
Likewise Resurrection (7th level, 1000gp consumed material component).
True Resurrection (9th level, 25,000gp consumed material component) removes all magical and non-magical diseases that afflicted the deceased at the time of its death.
Heal (6th level) ends any diseases affecting the target (among other things)
Hero's Feast (6th level, 1000gp consumed material component) cures all diseases in up to 12 creatures who consume it
Mass Heal (9th level) cures all diseases in any creatures you can see (and choose to target) within the 60 foot range (arguably you may have to heal them at least one hp for this to work)
To keep this list from getting too long, please only include items that specifically deal with disease, not ones that merely cast a spell that deals with disease.
Keoghtom's Ointment is a multiple-use consumable that fixes diseases (among other things)
Elixer of Health is a consumable that fixes diseases (amongst other things)
Periapt of Health makes you immune to disease while worn, and suppresses any existing ones.
A Night Hag's Heartstone can cure any diseases, but might be hard to obtain.
Potion of Vitality cures any diseases, but that's really a side-note compared to its major effects.
A Paladin's Lay on Hands ability says it can cure 1 disease if the Paladin spends 5 hp of its pool.
Transmutation Wizards' Master Transmuter ability allows them to remove all diseases (along with curses, poisons, hp damage) on a creature they touch with their transmuter's stone (consuming the stone).
Three days spent recuperating will allow you to make a CON save to gain advantage on saves against one disease (or poison). (This obviously is only useful against diseases where there is some existing saving throw mechanism to become cured.)