| O'Brien's Peerless Quintet | 1 | 1921 |
| O'Brien's State Street Seven | 2 | 1945 - 1947 |
| O'Bryant's Famous Original Washboard Band | 1 | 1925 |
| O'Bryant's Washboard Band | 5 | 1925 |
| O'Dell And Hudson | 1 | 1931 |
| O'Gorman Brothers | 1 | 1930 |
| The O'Leary Sisters | 1 | |
| O'Leary's Irish Minstrels | 2 | 1928 - 1947 |
| O'Rourke And Winston | 2 | 1931 |
| O. B. Masingill | 1 | 1955 |
| O. D. Holly And His Southern Troubadors | 1 | |
| O. J. McCormack | 2 | 1915 |
| O. K. Kirstiuk | 1 | 1927 |
| O. Kovaleva | 1 | |
| O. M. Maruszczak | 1 | 1928 |
| O.D.-Kören | 2 | 1927 |
| O. K. Rhythm Kings | 4 | 1931 |
| Oak Cliff T-Bone | 1 | 1930 |
| The Oak Mountain Four | 1 | 1930 |
| Oak Ridge Quartet | 5 | 1947 - 1952 |
| Oak Ridge Sacred Singers | 2 | 1929 |
| Oakie Jones | 5 | 1951 - 1952 |
| The Oakland Silvertones | 1 | |
| Oakland - Campbell - Burr | 2 | 1914 |
| Obed Pickard Of Station W.S.M. Nashville, Tenn. | 2 | 1927 - 1928 |
| The Obenkirchen Children's Choir | 3 | 1954 |
| Oberammergauer Zither Trio | 3 | 1916 - 1924 |
| Oberbayerische Bauernkapelle | 2 | 1917 |
| Obermusikmeister Adolf Becker | 1 | 1928 |
| The Obernkirchen Children's Choir | 8 | 1954 |
| Oceanic Dance Band | 3 | 1930 |
| Oceanic Dance Orchestra | 1 | 1930 |
| Ocie Smith | 2 | 1957 |
| Ocie Stockard And His Wanderers | 10 | 1937 - 1947 |
| Ocie Stockard And The Wanderers | 5 | 1937 - 1939 |
| Die Octavios | 4 | 1956 - 1957 |
| Octet A La Mode | 3 | 1968 |
| Octet And Chorus From "Pinafore" | 1 | 1907 |
| Octet Of Banduryst | 1 | |
| Oda Deckert | 1 | 1941 |
| Oddie McWinders | 1 | 1932 |
| Odeam Rakoto | 1 | |
| Odell Johnson And His Rhythm Ranch Pals | 2 | |
| Odelle Turner | 1 | 1952 |
| Odeon Danseorkester | 4 | 1931 - 1939 |
| Odeon Dansorkester | 1 | 1937 |
| Odeon Hawaiian Orkester | 1 | 1936 |
| Odeon Konstnärs Trion | 1 | 1913 |
| Künstler-Orchester Dajos Bela | 3 | 1927 - 1931 |
| Odeon Kyrko-Orkester | 1 | 1913 |
| Odeon Orchestra | 1 | |
| Odeon Orkester | 1 | 1913 |
| Odeon Orkestern | 1 | 1934 |
| Odeon Orkestr | 1 | |
| Odeon-Streichorchester | 3 | |
| Odeon Syncopators | 1 | 1926 |
| Odeon Tanz Orchester | 1 | 1928 |
| Odeon Tanz Orchester - Luigi Bernauer | 1 | |
| Odeon-Tanz-Musik | 1 | 1920 |
| Odeon-Hawaiian-Trio | 1 | 1936 |
| Odeon-Kammer-Orchester | 1 | 1928 |
| Odeon-kvartetten | 2 | 1913 - 1928 |
| Odeon-Militär-Orchester | 1 | |
| Odeon-Orchester | 6 | 1904 - 1923 |
| Odeon-Orkest | 1 | 1933 |
| Odeon-Orkester | 2 | 1920 |
| Odeon-Orkestern | 1 | 1933 |
| Odeon-Salon-Orchester | 1 | 1929 |
| Odeon-Sextetten | 1 | 1931 |
| Odeon-Tanz-Orchester | 2 | 1920 - 1928 |
| Odeon-Tanz-Streichorchester | 1 | 1950 |
| Odeon-Tanzorchester | 1 | 1928 |
| Odeons Dansorkester | 6 | 1930 - 1939 |
| Odette | 1 | 1954 |
| Odette And Ethel | 1 | 1926 |
| Odette Croisier | 1 | 1957 |
| Odette Turba-Rabier, Nadine Sautereau | 1 | 1947 |
| Odis Blanton And His Blue Star Rangers | 1 | 1954 |
| Odis Echols And His Melody Boys | 3 | |
| Odis Elder | 2 | 1934 - 1935 |
| The Odonians | 2 | 1933 - 1934 |
| Odus And Woodrow | 1 | 1938 |
| Odvar Lundby | 1 | 1953 |
| Ogden Nash | 4 | 1943 |
| Oglala Sioux Singers: W. Horncloud, Ben Sitting Up, Frank Afraid Of Horses | 1 | |
| Oiva Soini | 3 | 1928 - 1930 |
| Öivind Bergh's Danse-Orkester | 1 | 1948 |
| Ojwang, Okelo And Party | 1 | |
| The Okeh Atlanta Sacred Harp Singers | 2 | 1929 |
| OKeh Concert Band | 1 | 1918 |
| Okeh Dance Band | 2 | 1919 |
| Okeh Dance Orchestra | 3 | 1918 - 1920 |
| Okeh Marimba Band | 1 | 1921 |
| The Okeh Melodians | 3 | 1928 |
| OKeh Syncopators | 2 | 1924 - 1926 |
| The Okeh Syncopators | 1 | |
| The Okey Dokies Med Bent Fabricius Bjerres Orkester | 1 | 1952 |
| The Okey Dokies Med Bent Fabricius-Bjerres Kvartet | 1 | 1953 |
| The Okey Dokies | 6 | 1945 - 1953 |
| The Okey-Dokies Med Elo Magnussen Og Hans Orkester | 1 | |
| Okie Davis | 1 | |
| Okie Jones | 1 | 1951 |
| Oklahoma And The Westerners | 1 | |
| Oklahoma Ed Moody With The Six Westernaires | 4 | 1946 |
| Oklahoma Ed Moody | 3 | 1945 - 1949 |
| Oklahoma Orchestra | 5 | 1943 - 1947 |
| Oklahoma Songbirds | 1 | 1947 |
| Oklahoma Songbirds - Ann Bond And Mary Lou With Chuck Davis And The Gang | 1 | 1947 |
| Oklahoma Sweethearts | 6 | 1947 - 1951 |
| Oklahoma Wranglers | 2 | 1947 |
| The Oklahoma Wranglers | 19 | 1947 - 1954 |
| Die Oktavios | 1 | 1956 |
| Ola Martinez Y Su Trio Casino San Juan | 1 | 1948 |
| Ola Mossefinn | 4 | 1911 |
| Olaf Rudbeck | 1 | |
| Ólafur Pétursson | 1 | 1952 |
| Olav Hegland | 2 | 1939 - 1955 |
| Olav Werner | 4 | 1949 - 1952 |
| Olav Wernersen | 1 | 1952 |
| Olavi Virta | 36 | 1939 - 1957 |
| Olavi Virta Ja "Triola" Orkesteri | 1 | 1951 |
| Olavi Virta Ja Harmony Sisters | 2 | 1955 - 1956 |
| Olavi Virta Ja Metrotytöt | 2 | 1953 |
| Olavi Virta Sekä Scandia-Orkesteri | 1 | 1954 |
| Olavi Virta, Kipparikvartetti | 1 | 1955 |
| Olbrig's Zithertrio | 1 | 1928 |
| Old "Doc" McCrock And Bill Hart | 1 | 1949 |
| Old Black Joe's Band | 2 | 1907 |
| Old Brother Charlie And Daisy Mae | 1 | 1950 |
| Old Ced Odom And Lil "Diamonds" Hardaway | 3 | 1936 - 1937 |
| Old Drury Light Opera Company | 1 | 1944 |
| Old Fashioned Boys | 1 | 1931 |
| Old Fashioned Revival Hour Choir | 1 | |
| Old Fashioned Revival Hour Quartet | 5 | |
| Old Hank Penny | 1 | 1932 |
| Old Henry And His Musicians | 1 | 1926 |
| Old Man Oden | 1 | 1938 |
| Old Man Oden (Jimmie Oden) | 1 | 1934 |
| The Old Mill Dance Kings | 1 | 1928 |
| Old Quebec Trio | 1 | 1929 |
| Old Ragtimers | 1 | 1930 |
| The Old Sexton | 1 | 1929 |
| Old Smokey Twins | 7 | 1929 - 1931 |
| Old South Quartette | 1 | 1929 |
| Old Southern Sacred Singers | 8 | 1927 - 1930 |
| Old Timer | 1 | 1955 |
| Old Timer's Orchestra | 1 | 1940 |
| The Old Timer's Orchestra | 1 | 1939 |
| The Old Timers Skiffle Group | 1 | 1958 |
| The Old Timers | 3 | 1938 - 1958 |
| The Old Virginians | 2 | 1925 - 1926 |
| The Old-Time Players | 1 | 1931 |
| The Old-Timer's Orchestra | 2 | 1937 - 1938 |
| Olden Time Minstrels | 1 | 1904 |
| Ole Jensen | 10 | 1966 - 1968 |
| The Ole Jensen Ensemble | 1 | 1967 |
| The Ole Jensen Sextet | 1 | 1966 |
| Ole Monty | 28 | 1938 - 1956 |
| Ole Monty Og Dirch Passer | 1 | 1949 |
| Ole Monty Og Kaj Hill | 1 | 1952 |
| Ole Monty, Jørgen Bech And Jørgen Hansen | 1 | 1955 |
| Ole Mortensen | 1 | 1953 |
| Ole Og Mie | 1 | 1954 |
| Ole Olson | 3 | 1926 |
| Ole Rasmussen | 18 | 1945 - 1953 |
| Ole Rasmussen And His Cornhuskers | 5 | 1951 - 1952 |
| Ole Rasmussen And His Nebraska Cornhuskers | 10 | 1949 - 1953 |
| Ole Rasmussin Corn Huskers | 2 | 1945 |
| Ole Sonny Boy | 1 | 1956 |
| Ole Svenson | 1 | 1950 |
| Oleg Quist | 1 | 1933 |
| Olenska | 1 | |
| Olenska, Refren, Ruszala | 1 | |
| Olga Bibor's Gypsy Orchestra | 3 | 1919 - 1921 |
| Olga Bibor's Orchestra | 1 | 1920 |
| Olga Cavadias | 1 | |
| Olga Coelho | 2 | 1951 - 1952 |
| Olga En Sonia | 1 | 1955 |
| Olga Guillot | 5 | 1948 - 1956 |
| Olga Haley | 6 | 1924 - 1931 |
| Olga Lowina | 5 | 1950 - 1954 |
| Olga Massari Maida | 1 | 1921 |
| Olga Olgina | 2 | 1931 |
| Olga Samaroff | 4 | 1921 - 1923 |
| Olga, Elga And Eli Hudson | 1 | |
| Olga, Elgar And Eli Hudson | 1 | 1916 |
| Olimpia Balducci | 2 | 1920 - 1921 |
| Olimpia Boronat | 1 | 1973 |
| Olimpo Cardenas | 1 | |
| Olive Bloom, Spencer Dyke, Bernard Shore, B. Patterson Parker | 3 | |
| Olive Fox And Clarkson Rose | 1 | 1924 |
| Olive Fremstad | 2 | 1914 |
| Olive Gilbert | 2 | 1937 - 1945 |
| Olive Goff | 1 | 1925 |
| Olive Groves | 3 | 1932 - 1933 |
| Olive Groves And George Baker | 1 | 1931 |
| Olive Groves, Elsie Carlisle, Max Winn And Al Bowlly | 1 | 1931 |
| Olive Kline | 31 | 1912 - 1935 |
| Olive Kline – Harry MacDonough | 1 | 1915 |
| Olive Kline And Orpheus Quartet | 2 | 1919 |