These are the number-one singles of 1968 according to the Top 100 Singles chart in Cashbox magazine.
| Issue Date | Song | Artist |
| January 6 | "Hello, Goodbye" | The Beatles |
| January 13 | "I Heard It Through The Grapevine" | Gladys Knight & the Pips |
| January 20 | "Chain Of Fools" | Aretha Franklin |
| January 27 | "Judy in Disguise (With Glasses)" | John Fred And His Playboy Band |
| February 3 | "Green Tambourine" | The Lemon Pipers |
| February 10 | "Love is Blue" | Paul Mauriat |
| February 17 | ||
| February 24 | ||
| March 2 | ||
| March 9 | ||
| March 16 | ||
| March 23 | ||
| March 30 | "Valleri" | The Monkees |
| April 6 | ||
| April 13 | "Young Girl" | Gary Puckett & The Union Gap |
| April 20 | "Honey" | Bobby Goldsboro |
| April 27 | ||
| May 4 | ||
| May 11 | ||
| May 18 | "Tighten Up" | Archie Bell & the Drells |
| May 25 | "Mrs. Robinson" | Simon and Garfunkel |
| June 1 | ||
| June 8 | ||
| June 15 | ||
| June 22 | "This Guy's in Love with You" | Herb Alpert |
| June 29 | ||
| July 6 | ||
| July 13 | ||
| July 20 | "Jumpin Jack Flash" | The Rolling Stones |
| July 27 | "Grazing in the Grass" | Hugh Masekela |
| August 3 | "Lady Willpower" | Gary Puckett & The Union Gap |
| August 10 | "Classical Gas" | Mason Williams |
| August 17 | "Hello, I Love You" | The Doors |
| August 24 | "People Got to Be Free" | The Rascals |
| August 31 | ||
| September 7 | ||
| September 14 | "Harper Valley PTA" | Jeannie C. Riley |
| September 21 | "Hey Jude" | The Beatles |
| September 28 | ||
| October 5 | ||
| October 12 | ||
| October 19 | ||
| October 26 | ||
| November 2 | ||
| November 9 | "Those Were the Days" | Mary Hopkin |
| November 16 | ||
| November 23 | "Love Child" | Diana Ross & the Supremes |
| November 30 | ||
| December 7 | ||
| December 14 | "For Once in My Life" | Stevie Wonder |
| December 21 | "I Heard It Through the Grapevine" | Marvin Gaye |
| December 28 |