What episode do the cutie mark crusaders get cutie marks?

Answer 1

In Season 2 Episode 6, The Cutie Pox, Applebloom recieves several fake Cutie Marks caused by the sickness, but there is not an announced episode as of yet where any of the three get Cutie Marks.

Answer 2

The Cutie Mark Crusades appear in the following episodes. Bold texts indicates an episode revolving around one or more of them.

Season 1:

• Episode 1 "Friendship is Magic Part 1"
• Episode 12 "Call of the Cutie" (CMC are founded)
• Episode 17 "Stare Master"
• Episode 18 "The Show Stoppers"
• Episode 23 "The Cutie Mark Chronicles"

Season 2:

• Episode 1 "The Return of Harmony Part 1"
• Episode 3 "Lesson Zero"
• Episode 4 "Luna Eclipsed"
• Episode 5 "Sisterhooves Social" (Scootaloo does not appear)
• Episode 6 "The Cutie Pox"
• Episode 10 "Secret of My Excess"
• Episode 11 "Hearth's Warming Eve"
• Episode 12 "Family Appreciation Day"
• Episode 17 "Hearts and Hooves Day"
• Episode 18 "A Friend In Deed"
• Episode 23 "Ponyville Confidential"
• Episode 26 "A Canterlot Wedding Part 2"

Season 3

• Episode 4 "One Bad Apple"
• Episode 6 "Sleepless in Ponyville"
• Episode 8 "Apple Family Reunion" (only Apple Bloom and Babs Seed)

Answer 3

So far, they don't get one. There is an episode named "Cutie Pox" where apple bloom gets many, but they end up going away. If they'll ever get them or not, nobody knows. I assume if they were to get their cutie marks, it would probably be the very last episode ever of mlp. That's usually how those types of plots go.