While developing 5th Edition D&D material for my Skirmisher Publishing, I found myself wishing I had a list of all spells from the Player's Handbook that have the ritual tag associated with them, and so I went ahead and created one! I figured other people might find such a list useful and have, accordingly, posted it here twice, once with the spells simply in alphabetical order and once with them organized by level. I have also marked spells requiring Concentration, as this is an important thing to keep track of in 5th Edition and a caster can only keep one such spell in effect at a time. Be sure to also check out our lists of  5th Edition D&D "Abjuration" Spells, 5th Edition D&D "Divination" Spells, 5th Edition D&D 'Illusion' Spells, and 5th Edition D&D 'Necromancy' Spells! 

5th Edition Ritual Spells (Alphabetical)

Alarm (1st)
Animal Messenger (2nd)
Augury (2nd)
Beast Sense (C) (2nd)
Commune (5th)
Commune with Nature (5th)
Comprehend Languages (1st)
Contact Other Plane (5th)
Detect Magic (C) (1st)
Detect Poison and Disease (C) (1st)
Divination (4th)
Drawmij's Instant Summons (6th)
Feign Death (3rd)
Find Familiar (1st)
Forbiddance (6th)
Gentle Repose (2nd)
Identify (1st)
Illusory Script (1st)
Leomund's Tiny Hut (3rd)
Locate Animals or Plants (2nd)
Magic Mouth (2nd)
Meld Into Stone (3rd)
Phantom Steed (3rd)
Purify Food and Drink (1st)
Rary's Telepathic Bond (5th)
Silence (C) (2nd)
Speak with Animals (1st)
Tenser's Floating Disk (1st)
Unseen Servant (1st)
Water Breathing (3rd)
Water Walk (3rd)

5th Edition Ritual Spells (By Level)

Alarm (1st)
Comprehend Languages (1st)
Detect Magic (C) (1st)
Detect Poison and Disease (C) (1st)
Find Familiar (1st)
Identify (1st)
Illusory Script (1st)
Purify Food and Drink (1st)
Speak with Animals (1st)
Tenser's Floating Disk (1st)
Unseen Servant (1st)
Animal Messenger (2nd)
Augury (2nd)
Beast Sense (C) (2nd)
Gentle Repose (2nd)
Locate Animals or Plants (2nd)
Magic Mouth (2nd)
Silence (C) (2nd)
Feign Death (3rd)
Leomund's Tiny Hut (3rd)
Meld Into Stone (3rd)
Phantom Steed (3rd)
Water Breathing (3rd)
Water Walk (3rd)
Divination (4th)
Commune (5th)
Commune With Nature (5th)
Contact Other Plane (5th)
Rary's Telepathic Bond (5th)
Drawmij's Instant Summons (6th)
Forbiddance (6th)