Oricon has revealed the top-selling light novels of 2018 in Japan. This list covers sales surveyed from November 20, 2017 to November 18, 2018.
Details:
| Estimated Sales in Period | Title | Publisher | |
| 1 | 807,693 | Overlord | Enterbrain |
| Writer: Kugane Maruyama/ Illustration: so-bin | |||
| 2 | 630,889 | Konosuba - God's Blessing on This Wonderful World! | Kadokawa |
| Writer: Natsume Akatsuki/ Illustration: Kurone Mishima | |||
| 3 | 626,952 | The Irregular at Magic High School | ASCII Media Works |
| Tsutomu Satou Illustration: Kana Ishida | |||
| 4 | 619,031 | Re:Zero | Kadokawa |
| Writer: Tappei Nagatsuki/ Illustration: Shinichirou Otsuka | |||
| 5 | 539,277 | That Time I Got Reincarnated as a Slime | Micro Magazine |
| Writer: Fuse/ Illustration: Mitz Vah | |||
| 6 | 478,242 | The Ryuo's Work is Never Done! | SB Creative |
| Writer: ShirÅ Shiratori/ Illustration: Shirabi/ Supervision: Saiyuki | |||
| 7 | 426,794 | Sword Art Online: Progressive | ASCII Media Works |
| Story: Reki Kawahara Illustration: abec | |||
| 8 | 393,949 | Classroom of the Elite | Media Factory |
| Writer: Syohgo Kinugasa/ Illustration: Shunsaku Tomose | |||
| 9 | 371,626 | Sword Art Online | ASCII Media Works |
| Story: Reki Kawahara Illustration: abec | |||
| 10 | 350,960 | No Game No Life | Media Factory |
| Writer/Illustration: Yuu Kamiya |