| Opening Theme | Sonic Underground | |
| # | Episode Name | Song Name |
| 1 | Wedding Bell Blues | When Tomorrow Comes |
| 2 | To Catch a Queen | Have You Got the 411? |
| 3 | Mobodoon | I Found My Home |
| 4 | The Price of Freedom | Money Can’t Buy |
| 5 | Underground Masquerade | Let the Good Times Roll |
| 6 | Tangled Webs | Children Light the Way |
| 7 | The Deepest Fear | Face Your Fear |
| 8 | Who Do You Think You Are | We Need to be Free |
| 9 | The Last Resort | Listen to Your Heart |
| 10 | Come Out Wherever You Are | Society Girl |
| 11 | Winner Fakes All | Built for Speed |
| 12 | A Hedgehog’s Home is Her Castle | Let’s Do It to It |
| 13 | Artifact | You Can’t Own Everything You See |
| 14 | Bug! | Never Give Up |
| 15 | Sonic Tonic | Faster |
| 16 | Friend or Foe | Things Aren’t Always What They Seem |
| 17 | Head Games | Take a Chance |
| 18 | When in Rome . . . | Where There’s a Will There’s a Way |
| 19 | The Jewel in the Crown | Cosmic Dance |
| 20 | Three Hedgehogs and a Baby | Being a Kid is Cool |
| 21 | Dunes Day | True Blue Friend |
| 22 | Mummy Dearest | We Are Sonic Underground |
| 23 | Hedgehog in the Iron Mask | Part of the Problem |
| 24 | Six is a Crowd | I Can Do That for You |
| 25 | Flying Fortress | No One is an Island |
| 26 | No Hedgehog is an Island | Learn to Overcome |
| 27 | Getting to Know You | Harmony |
| 28 | New Echidna in Town | The Mobius Stomp |
| 29 | Harmony or Something | Together |
| 30 | Country Crisis | How You Play the Game |
| 31 | Haircraft in Space | Don’t be a Backstabber |
| 32 | Healer | We’re the Sonic Underground |
| 33 | Sonia’s Choice | Why is it Never Easy |
| 34 | The Big Melt | Fun in the Sun |
| 35 | Sleepers | Have it All Again |
| 36 | Bartleby the Prisoner | Justice Calling |
| 37 | The Art of Destruction | Sound of Freedom |
| 38 | The Pendant | Liberty Rocks |
| 39 | Virtual Danger | Don’t Let Your Guard Down |
| 40 | Beginnings | Someday |