This is the complete list of number-one singles in Finland in 2021 according to the Official Finnish Charts. The list on the left side of the box (Suomen virallinen singlelista, "the Official Finnish Singles Chart") represents physical and digital track sales as well as music streaming, and the one on the right side (Suomen virallinen radiosoittolista, "the Official Finnish Airplay Chart") represents airplay.
| Official Finnish Singles Chart | Official Finnish Airplay Chart | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Issue date | Song | Artist(s) | Reference(s) | Issue date | Song | Artist(s) | Reference(s) | ||
| Week 1 | "Treenaa" | Antti Tuisku | Week 1 | "Frida" | Behm | ||||
| Week 2 | "Without You" | The Kid Laroi | Week 2 | ||||||
| Week 3 | "Drivers License" | Olivia Rodrigo | Week 3 | ||||||
| Week 4 | Week 4 | ||||||||
| Week 5 | Week 5 | "Syntisten pöytä" | Erika Vikman | ||||||
| Week 6 | Week 6 | "Dinosauruksii" | Ellinoora | ||||||
| Week 7 | "Me ei mennä rikki" | Gasellit | Week 7 | ||||||
| Week 8 | "Dark Side" | Blind Channel | Week 8 | ||||||
| Week 9 | "Piilotan mun kyyneleet" | Haloo Helsinki! | Week 9 | ||||||
| Week 10 | Week 10 | ||||||||
| Week 11 | Week 11 | ||||||||
| Week 12 | Week 12 | ||||||||
| Week 13 | "Steppasin Partyy" | Yb026 | Week 13 | "Piilotan mun kyyneleet" | Haloo Helsinki | ||||
| Week 14 | "Montero (Call Me by Your Name)" | Lil Nas X | Week 14 | ||||||
| Week 15 | Week 15 | "Dinosauruksii" | Ellinoora | ||||||
| Week 16 | Week 16 | "Piilotan mun kyyneleet" | Haloo Helsinki | ||||||
| Week 17 | Week 17 | ||||||||
| Week 18 | Week 18 | ||||||||
| Week 19 | "Pettäjä" | Sanni | Week 19 | ||||||
| Week 20 | "Montero (Call Me by Your Name)" | Lil Nas X | Week 20 | ||||||
| Week 21 | "Dark Side" | Blind Channel | Week 21 | ||||||
| Week 22 | "Zitti e buoni" | Måneskin | Week 22 | ||||||
| Week 23 | Week 23 | ||||||||
| Week 24 | "I Wanna Be Your Slave" | Week 24 | |||||||
| Week 25 | Week 25 | "Aavikko" | Lauri Tähkä | ||||||
| Week 26 | "Vauhti kiihtyy" | Portion Boys | Week 26 | ||||||
| Week 27 | "I Wanna Be Your Slave" | Måneskin | Week 27 | ||||||
| Week 28 | "Vauhti kiihtyy" | Portion Boys | Week 28 | ||||||
| Week 29 | "Bad Habits" | Ed Sheeran | Week 29 | "Taipumaton" | Kaija Koo | ||||
| Week 30 | Week 30 | ||||||||
| Week 31 | "Stay" | The Kid Laroi and Justin Bieber | Week 31 | "Lupaan" | Behm | ||||
| Week 32 | Week 32 | "Bad Habits" | Ed Sheeran | ||||||
| Week 33 | Week 33 | ||||||||
| Week 34 | Week 34 | ||||||||
| Week 35 | Week 35 | ||||||||
| Week 36 | Week 36 | ||||||||
| Week 37 | "Samma gamla vanliga" (remix) | Cledos, and Averagekidluke | Week 37 | ||||||
| Week 38 | Week 38 | ||||||||
| Week 39 | Week 39 | ||||||||
| Week 40 | Week 40 | ||||||||
| Week 41 | Week 41 | "Tulikärpäset" | Haloo Helsinki | ||||||
| Week 42 | Week 42 | ||||||||
| Week 43 | Week 43 | ||||||||
| Week 44 | Week 44 | ||||||||
| Week 45 | Week 45 | ||||||||
| Week 46 | Week 46 | ||||||||
| Week 47 | Week 47 | "Easy on Me" | Adele | ||||||
| Week 48 | Week 48 | ||||||||
| Week 49 | Week 49 | ||||||||
| Week 50 | "ABCDEFU" | Gayle | Week 50 | ||||||
| Week 51 | "Snowman" | Sia | Week 51 | "Merry Christmas" | Ed Sheeran and Elton John | ||||
| Week 52 | "Joulun kanssas jaan" | Haloo Helsinki | Week 52 | "Easy on Me" | Adele | ||||