This is the complete list of number-one singles in Finland in 2018 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 | "Popkorni" | JVG | Week 1 | "Muitaki ihmisii" | Vesala | ||||
| Week 2 | Week 2 | "Tuntematon" | Haloo Helsinki! | ||||||
| Week 3 | Week 3 | ||||||||
| Week 4 | "Jättiläinen" | Pyhimys (featuring Aksel Kankaanranta) | Week 4 | ||||||
| Week 5 | "Popkorni" | JVG | Week 5 | ||||||
| Week 6 | "Vedän sut henkeen" | Antti Tuisku | Week 6 | ||||||
| Week 7 | "Texas" | Haloo Helsinki | (featuring JVG) | Week 7 | "Tornado" | Evelina | |||
| Week 8 | "Rikkinäinen prinsessa" | Nikke Ankara | Week 8 | ||||||
| Week 9 | Week 9 | ||||||||
| Week 10 | "Sun vika" | Evelina | Week 10 | "Olisitpa sylissäni" | Antti Ketonen | ||||
| Week 11 | "Rikkinäinen prinsessa" | Nikke Ankara | Week 11 | ||||||
| Week 12 | "Pornoo" | Sanni | Week 12 | ||||||
| Week 13 | Week 13 | ||||||||
| Week 14 | "Satutat mua" | Tippa | Week 14 | ||||||
| Week 15 | "Timanttei" | Mikael Gabriel | Week 15 | ||||||
| Week 16 | Week 16 | ||||||||
| Week 17 | "Kevät" | Adi L Hasla (featuring Pihlaja) | Week 17 | "Väärään suuntaan" | Jenni Vartiainen | ||||
| Week 18 | Week 18 | "Olisitpa sylissäni" | Antti Ketonen | ||||||
| Week 19 | Week 19 | ||||||||
| Week 20 | Week 20 | ||||||||
| Week 21 | Week 21 | ||||||||
| Week 22 | Week 22 | "Väärään suuntaan" | Jenni Vartiainen | ||||||
| Week 23 | Week 23 | "Kuka näkee sut" | Juha Tapio | ||||||
| Week 24 | "Solo" | Clean Bandit (featuring Demi Lovato) | Week 24 | ||||||
| Week 25 | "Jacuzzi" | Sanni | Week 25 | ||||||
| Week 26 | "Solo" | Clean Bandit (featuring Demi Lovato) | Week 26 | "Nyt on lähtö" | Vesala | ||||
| Week 27 | "XTC" | Lukas Leon, Etta and Cheek | Week 27 | "Kaksi ihmistä" | Haloo Helsinki | ||||
| Week 28 | Week 28 | ||||||||
| Week 29 | "Solo" | Clean Bandit (featuring Demi Lovato) | Week 29 | ||||||
| Week 30 | Week 30 | ||||||||
| Week 31 | Week 31 | ||||||||
| Week 32 | "Yhen elämän juttu" | Abreu | Week 32 | ||||||
| Week 33 | "In My Mind" | Dynoro and Gigi D'Agostino | Week 33 | "Supervoimii" | Elastinen | ||||
| Week 34 | Week 34 | ||||||||
| Week 35 | Week 35 | ||||||||
| Week 36 | Week 36 | ||||||||
| Week 37 | Week 37 | ||||||||
| Week 38 | "I Love It" | Kanye West and Lil Pump | Week 38 | ||||||
| Week 39 | "Falling Down" | Lil Peep and XXXTentacion | Week 39 | "Kuka näkee sut" | Juha Tapio | ||||
| Week 40 | Week 40 | "Me ollaan runo" | Anna Puu | ||||||
| Week 41 | Week 41 | "Mä en pelkää" | Lauri Tähkä | ||||||
| Week 42 | Week 42 | ||||||||
| Week 43 | "Loppuun asti" | Elastinen | Week 43 | "Ilves" | Anssi Kela | ||||
| Week 44 | "Sweet but Psycho" | Ava Max | Week 44 | ||||||
| Week 45 | Week 45 | ||||||||
| Week 46 | "Thank U, Next" | Ariana Grande | Week 46 | ||||||
| Week 47 | "Sweet but Psycho" | Ava Max | Week 47 | ||||||
| Week 48 | Week 48 | ||||||||
| Week 49 | Week 49 | "Sweet but Psycho" | Ava Max | ||||||
| Week 50 | Week 50 | "Mä en pelkää" | Lauri Tähkä | ||||||
| Week 51 | Week 51 | "Sweet but Psycho" | Ava Max | ||||||
| Week 52 | "All I Want for Christmas Is You" | Mariah Carey | Week 52 | ||||||