| 2021 LCS season | |
|---|---|
| League | LCS |
| Sport | League of Legends |
| Duration |
|
| Number of teams | 10 |
| TV partner(s) | English: Twitch, YouTube |
| Lock In | |
| Winner | Team Liquid |
| Runners-up | Cloud9 |
| Spring | |
| Winner | Cloud9 |
| Runners-up | Team Liquid |
| Top seed | Cloud9 |
| Season MVP | Robert "Blaber" Huang |
| Summer | |
| Winner | 100 Thieves |
| Runners-up | Team Liquid |
| Top seed | Team SoloMid |
| Season MVP | Mingyi "Spica" Lu |
The 2021 LCS season was the ninth season of the League Championship Series (LCS), a professional esports league for the video game League of Legends. The season was preceded a new preseason tournament, the LCS Lock In, which ran from January 15 to 31, 2021. The season was divided into two splits: Spring and Summer. The Spring Split began on February 5 and culminated with the Mid-Season Showdown finals on April 11, 2021. The Summer Split began on June 4 and culminated with the LCS Championship Final on August 1, 2021.
In 2021, the LCS underwent significant changes. The spring split regular season became a six-week double round-robin, while the spring playoffs were renamed the Mid-Season Showdown. The summer split regular season expanded to a nine-week triple round-robin format. The spring and summer regular season records were combined to determine LCS Championship seeding. Additionally, the league rebranded as the League Championship Series and introduced a new logo and mottos.
Cloud9 won the spring split playoffs, qualifying them for the 2021 Mid-Season Invitational. In the LCS Championship playoffs, 100 Thieves, Team Liquid, and Cloud9 claimed the first, second, and third positions, respectively, earning qualifications to the 2021 World Championship.