Song: "Knock Knock Who's There"
Artist: Mary Hopkin
Peak position on the Cashbox Singles chart: #86
Number of weeks on the Cashbox Singles chart: 7
(5 weeks in the Top 100)
Weekly data:
| Week ending | Rank | Title | Artist | Label |
|---|---|---|---|---|
| November 25, 1972 | 106 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| December 2, 1972 | 95 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| December 9, 1972 | 88 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| December 16, 1972 | 86 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| December 30, 1972 | 119 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| January 6, 1973 | 99 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
| January 13, 1973 | 97 | Knock Knock Who's There | Mary Hopkin | Apple 1855 |
Rankings greater than 100 are from the Cashbox 'Looking Ahead' charts.