| |||||||||||||||||||||||||||||||||||||||||||||||||||||
| December 31 (approx.) | ||
|---|---|---|
 SZ | Mityan leaves. | |
 AMS | Mykiih leaves. | |
| December 31 | ||
 N7 | Thresh and Venkz join. Luckycharmz and Nikels leave. | |
 WB | Brolic, Farma, FLawLesS, KingGudnite, and Waterhead join. | |
| December 30 | ||
 J4L | 2ReaL, HumanJesus, and KlinK join. | |
| December 29 | ||
 KCP | Chaaxter, Control, Cxllum, Harry, and Hawqeh leave. | |
| December 28 | ||
 vP | Bielzinho, EliTz, JHustleR, Krevz, Scarz, and KBR (Coach) join. | |
| NGL Masters Division 2020 Stage 1 will begin on January 8. | ||
| December 27 | ||
| ArenaOn Open 2020 and remainder of 2020 ArenaOn season are canceled. | ||
 EFY | BBConor, Fusionz, Genesis, Gismo, and QwiKeR join. | |
 UT3 | GamerVM, RadiaNt, Xemzed, Xpiry, and xRoToo join. | |
| December 26 | ||
 RUSH | Nicochan joins as substitute. | |
| December 25 | ||
 CAG | CoD Division disbands. Current, Ngt, Nicochan, NiRu, Noy, and Sokube (Coach/Manager) leave. | |
| December 24 | ||
 ACE1 | ShadizT and Supreeme rejoin. | |
 FG | Rizee and Swizzy join. | |
 BC | MaxedZ leaves. | |
 RVNS | MaxedZ joins. | |
| Call of Duty League 2020 season format changes from round robin to weekly tournaments. | ||
 CHI | MBoZe joins as substitute. | |
| December 23 | ||
| BC | RenKoR leaves. | |
 PSH | MethodZ and RenKoR join. | |
 FTW | Team merges with  TG Paragon to form  Paragon FTW for NGL Masters Division 2020. Rufia joins. | |
 TPF | TG Paragon and  FTW Esports merge teams to form Paragon FTW for NGL Masters Division 2020. KidzZ, Rufia, SXNNY, Visions, and Voltrix join. | |
 VTN | CRZY, Morte, Pepo, RippeR, and Slayeer join. | |
 GTZ | Bhconc joins. Varandas leaves. | |
| December 23 (approx.) | ||
 777 | HardTrevs, Nano, Sheed, Soldier, and Suricato leave. | |
| December 22 | ||
 FNX | Divinity, FriiZ, Meemo, SamBaldy, Trance, and Powerhouse (Coach) join. | |
  GroundCODBestCOD   Aspire eSports in the UMG Gaming Prime $1000 5v5 S&D 2019-12-22. | ||
| lildawgs HKv1 in the GameBattles Premium $1000 4v4 S&D 2019-12-22. | ||
 Virtue Gaming  NexT Team in the ArenaOn Série A 2020 Season 1. | ||
 MAF | ShadizT and Supreeme leave. | |
| December 21 | ||
| ACE1 | Rizee leaves. | |
| EFY | Aether, Alfoon, Glaaix, iTorres, and Ninjaso leave. | |
| PSH | Vikul joins. | |
AON | NexT Team  4LF4 Team in the ArenaOn 2020 Season 1 5v5 Variant 4. | |
| BC | Vikul leaves. | |
| December 20 | ||
 6G | FA5TBALLA joins. JFatal leaves. | |
| Crimsix & Shotzzy iLLeY & Clayster in the BoomTV Code Red 2019-12-20. | ||
 NexT | Horid joins. | |
 Kawaii Kiwis, Eternal, Unit3k, XLYNX Esports, Ravens Esports,Paragon FTW, Veteranos eSports, Pushing Gaming, and  Killabeez Esports announced as NGL Masters Division 2020 Stage 1 teams. | ||
 III | Clutchery, Huhdle, Magik, Prophet, and UntitleD join. | |
| December 19 (approx.) | ||
 LUC | Avo, Cobra, Deezy, Haz, and Vadex leave. | |
| ACE1 | KonGz and Radiz join. | |
| December 19 | ||
 KBZ | Drome, Genue, Knowcks, Lupiz, and Vidal join. | |
 GLTY | Foncho, MonGhoster, Phenom, PowInfinity, and Siinless join. | |
 JKS | Breiko, HackeR, Nodish, Quantum, Rakten, Revay, Espia (Coach), and KondeliuS (Manager) join. | |
| December 18 | ||
 F/A | Glory retires. | |
| PSH | ReeaL joins. EriKBooM rejoins. | |
| ACE1 | iPulse leaves. | |
| December 17 | ||
 KWK | Aether, Alfoon, Glaaix, iTorres, Ninjaso, CHUFI (Coach), and Hernan (Manager) join. | |
 FURY | CronusKun and JamesJHR join. Flanners, ManOfChicken, and Middoh rejoin. | |
| December 16 (approx.) | ||
| GETB | Archivz, Jimbo, Mosh, and TcM leave. | |
 OXY | Anthrax, Copier, ExiB, Kade, and Pawns leave. | |
| December 16 | ||
| BC | EriKBooM and ReeaL leave. | |
 OVRT | Cruze, Fate, Hybrid, Killerpie, Tyson, and Camerxn (Coach) join. | |
| AMS | AshTastic, Mykiih, RyanGray, TypicalNerd, and ZoSoviet join. | |
| December 15 | ||
| F/A | RobbieB3319 retires. | |
 Bravado Gaming LNR All Stars in the ACGL 2000 Series 2019-12-15. | ||
 Black Claw eSports  For The Win Esports in the EEG Malta 3.0 2019. | ||
| Doug Censor Martin v3 Lewtee challenge v3 in the GameBattles EU Challengers: 2000 Series Tournament #5. | ||
 UYU  Aspire eSports in the GameBattles NA Challengers: 2000 Series Tournament #5. | ||
| December 14 (approx.) | ||
| GETB | Archivz, Jimbo, Mosh, ProFeeZy, and TcM join. | |
 HYXR | Gunna (Coach) leaves. | |
| December 14 | ||
 A2M | JLags, Legal, Miyagi, Sher, and VeXeD join. | |
GB |  farmer wants a wife shelby v2 in the GameBattles AP Challengers: 2000 Series Tournament #5. | |
| NexT | Gabz leaves. | |
 4LF4 | JHustleR leaves. | |
 ASP | Davpadie, Evasion, Standy, Swarley, and Zinx join. | |
 CHAO | Hate, Juju, Katani, Koots, Noysii, and Gunna (Coach) join. | |
| December 13 | ||
| 6G | GloFrosty, JFatal, Owakening, Reaper, and Willett join. | |
 UYU | MRuiz joins. | |
| December 12 | ||
 LAG | Blazt joins as substitute. | |
 PrB | Caio, Faake, Lorosco, Martino, Mirolla, and RicK join. | |
 NK | Mirolla leaves. | |
| 4LF4 | Martino leaves. | |
| UYU | Tisch leaves. | |
 DAL | Tisch joins as substitute. | |
| GTZ | EPiK, Phoeniix, and Pretoo join. KPainz, Neto, and Stun leave. | |
| OXY | Copier, ExiB, Kade, Pawns, and Thrax leave. | |
| December 11 | ||
 OGLA | Chino and Goonjar join as substitutes. | |
| FG | Fenix leaves. | |
 FLA | MaNiaC joins as substitute. | |
 OG | MaNiaC (Streamer) leaves. | |
| December 10 | ||
 Team Alpha  Team Delta in the Modern Warfare Streamer Invitational 2019. | ||
| December 9 (approx.) | ||
| LUC | Deezy joins. Tarpy leaves. | |
| December 9 | ||
| CHI | Sender (Head Coach) joins. | |
 E6 | Sender (Coach) leaves. | |
 TaL | aRoMa and Cxllum leave. | |
| SZ | AliceWonderland, Duffle, MiAKi, Mityan, NevvtonX, and Nekokan (Coach) join. | |
| MAF | ShadizT and Supreeme join. Draken and Relays leave. | |
| December 8 | ||
| SxD Esports in the Red Bull AdrenaLAN 2019. | ||
| Alpha- ReeceImissyou in the GameBattles NA Challengers: 2000 Series Tournament #4. | ||
| Doug Censor Martin v2 Pigeons chests in the GameBattles EU Challengers: 2000 Series Tournament #4. | ||
| Bravado Gaming iEnvy in the ACGL 2000 Series 2019-12-08. | ||
AON | NexT Team  Furious Gaming in the ArenaOn 2020 Season 1 5v5 Variant 3. | |
 R5 | Taz joins. Dupin leaves. | |
| December 7 | ||
| ACE1 | ShadizT leaves. | |
 SNG | Chain joins. Maple rejoins. Insight will remain with the team. | |
| TaL | Maple leaves. | |
Never Back Down  Unjustified Gaming Red in the AGN New Jersey 2020. | ||
| IDontSeeUsLosing Free800 in the UMG Gaming Fall Ladder 2019 Team Playoffs. | ||
| Shelby Superman in the GameBattles AP Challengers: 2000 Series Tournament #4. | ||
 Libalent Vertex  Rush Gaming in the CDC Japan National Cup 2020 Preseason Tournament. | ||
| December 6 | ||
| CHI | General joins as substitute. | |
| December 5 | ||
| Call of Duty League Ruleset v1.4 is released. | ||
| CHI | x2Pac ThuGLorD (Analyst) joins. | |
 FaZe | GRVTY leaves. | |
 ATL | GRVTY and JurNii join as substitutes. | |
| ACE1 | Supreeme leaves. | |
 Peak | Brechy, Dusty, FrimJ, RiRi, and Virgis join. | |
 TALY | Dihlz, FaKeZ, OMGui, Stukas, and Suzano join. | |
| 777 | Dihlz and Stukas leave. | |
| December 3 | ||
 SEA | TeddyRecKs (S&D Analyst) joins. | |
| December 2 | ||
| FLA | Frosty, Havok, Maux, Prestinni, Skyz, and Atura (Coach) join. | |
 ATH | PaceR and Teskiy join. Conbix and Return leave. | |
 LG | Skyz leaves. | |
 eU | Prestinni leaves. | |
 GEN | Havok and Maux leave. | |
| December 1 (approx.) | ||
 DVT | 6IX, Chingy, Heaven, Inique, and Khau join. | |
| December 1 | ||
| Querella qualifies for NGL Masters Division 2020 Stage 1. | ||
| F/A | Bravado Gaming  ViNCO Gaming in the After Action Report Summer Invitational 2019. | |