| O Desolation |
6 |
| O Quam Tristis |
5 |
| O Rappa |
10 |
| O Surto |
3 |
| O Teatro Mágico |
10 |
| O' Cealleigh |
17 |
| O'Brother |
3 |
| O'Connor |
12 |
| O'Jays |
5 |
| O'Ryan |
15 |
| O+S |
3 |
| O-Town |
54 |
| O-Zone |
44 |
| O. Torvald |
3 |
| O.A.R. |
142 |
| O.A.R. (Of A Revolution) |
6 |
| O.C. Supertones (The) |
6 |
| O.Children |
4 |
| O.L.D |
5 |
| O.N.A. |
17 |
| O.R.O. (Onde Radio Ovest) |
13 |
| O.S.I. |
26 |
| O.S.T.R. |
19 |
| O.Torvald |
3 |
| O.a.r. |
7 |
| O.a.r. (of A Revolution) |
5 |
| OAG |
14 |
| OBK |
43 |
| OCEANS OF SADNESS |
4 |
| OFF! |
10 |
| OFFis |
5 |
| OHL |
14 |
| OK Go |
70 |
| OKS |
3 |
| OLD (O.L.D.) |
3 |
| OLIVIA |
4 |
| OMC |
13 |
| ON/OFF |
3 |
| OPM |
33 |
| OSI |
9 |
| OST |
20 |
| OST LEXX - Brigadoom |
3 |
| OST Little Mermaid |
3 |
| OST Mamma Mia! |
3 |
| OST Sweeney Todd |
5 |
| OST «Алиса в стране чудес» |
3 |
| OST Стиляги |
3 |
| OV7 |
17 |
| OXO |
11 |
| Oai Star |
3 |
| Oak Ridge Boys |
7 |
| Oakenfold |
4 |
| Oasis |
335 |
| Oathean |
8 |
| Obadiah Parker |
7 |
| Obed Thompson |
3 |
| Obie Bermudez |
49 |
| Obits |
9 |
| Obituary |
89 |
| Objektif |
24 |
| Obk |
7 |
| Obliveon |
31 |
| Obliviate! |
4 |
| Oblivio |
5 |
| Oblivion Dust |
53 |
| Obrint Pas |
19 |
| Obscene Eulogy |
4 |
| Obscura |
33 |
| Obscurcis Romancia |
3 |
| Obscurity |
3 |
| Obsession |
9 |
| Obsessive Compulsive |
4 |
| Obtained Enslavement |
21 |
| Obús |
30 |
| Oc Supertones |
3 |
| Occult |
5 |
| Ocean |
74 |
| Ocean Blue |
15 |
| Ocean Blue (The) |
6 |
| Ocean Chief |
5 |
| Ocean Colour Scene |
221 |
| Ocean Drive |
3 |
| Ocean Is Theory |
6 |
| Ocean Voyager |
4 |
| OceanLab |
5 |
| Oceana |
25 |
| Oceana (USA) |
3 |
| Oceania |
10 |
| Oceanlab |
23 |
| Oceanlab feat. Justine Suissa |
3 |
| Oceano |
30 |
| Oceans Ate Alaska |
3 |
| Oceans Of Sadness |
27 |
| Oceans Upon Us |
5 |
| Oceansize |
50 |
| Oconnor Hazel |
5 |
| Oconnor Sinead |
4 |
| Octane |
6 |
| Octavia |
60 |
| Octavia Sperati |
23 |