| Club: | RB Leipzig |
| Season: | 2018–19 |
| Ownertitle: | Chairman |
| Owner: | Oliver Mintzlaff |
| Manager: | Ralf Rangnick |
| Stadium: | Red Bull Arena |
| League: | Bundesliga |
| Cup1: | DFB-Pokal |
| Cup2: | UEFA Europa League |
| League Topscorer: | Timo Werner (16) |
| Season Topscorer: | Yussuf Poulsen Timo Werner (19 each) |
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| Prevseason: | 2017–18 |
| Nextseason: | 2019–20 |
The 2018–19 RB Leipzig season was the 10th season in the club's history and 3rd consecutive and overall season in the top flight of German football, the Bundesliga, having been promoted from the 2. Bundesliga in 2016. In addition to the domestic league, RB Leipzig also participated in the season's editions of the domestic cup, the DFB-Pokal, and the second-tier continental cup, the UEFA Europa League. This was the 9th season for Leipzig in the Red Bull Arena, located in Leipzig, Saxony, Germany. The season covers a period from 1 July 2018 to 30 June 2019.
| Player | From | Source | |||||||
|---|---|---|---|---|---|---|---|---|---|
| 3 | DF | Marcelo Saracchi |  River Plate | Transfer | Summer | 2023 | €12,000,000 | ||
| 8 | MF |  Amadou Haidara |  RB Salzburg | Transfer | Winter | 2023 | Undisclosed | ||
| 18 | MF | Emile Smith Rowe | Arsenal FC | Loan | Winter | 2019 | N/A | ||
| 20 | FW |  Matheus Cunha | FC Sion | Transfer | Summer | 2023 | €15,000,000 | ||
| 21 | GK | Marius Müller | 1. FC Kaiserslautern | Loan return | Summer | 2019 | Free | ||
| 22 | DF |  Nordi Mukiele | Montpellier | Transfer | Summer | 2023 | €16,000,000 | ||
| 33 | DF |  Atınç Nukan | Beşiktaş | Loan return | Summer | 2020 | Free | ||
| 35 | MF |  Massimo Bruno | Anderlecht | Loan return | Summer | 2019 | Free | ||
| – | MF | Elias Abouchabaka | RB Leipzig U19 | Promoted | Summer | 2021 | Free | ||
| – | MF | Felix Beiersdorf | Chemie Leipzig] | Loan return | Summer | 2021 | Free | ||
| – | FW |  Omer Damari | Maccabi Haifa | Loan return | Summer | 2018 | Free | ||
| – | MF | Agyemang Diawusie | Wehen Wiesbaden | Loan return | Summer | 2020 | Free | ||
| – | MF | Vitaly Janelt | VfL Bochum | Loan return | Summer | 2021 | Free | ||
| — | DF | Anthony Jung | Brøndby IF | Loan return | Summer | 2019 | Free | ||
| — | MF |  Zsolt Kalmár |  Dunajská Streda | Loan return | Summer | 2019 | Free | ||
| — | DF | Dominic Minz | RB Leipzig U19 | Promoted | Summer | Undisclosed | Free |
| Player | To | Source | ||||||
|---|---|---|---|---|---|---|---|---|
| 1 | GK | Fabio Coltorti | End of contract | Summer | Free | |||
| 3 | DF | Bernardo | Brighton & Hove Albion | Transfer | Summer | €10,000,000 | ||
| 8 | MF | Naby Keïta | Liverpool | Transfer | Summer | €60,000,000 | ||
| 18 | FW | Ademola Lookman | Everton | Loan return | Summer | Free | ||
| 20 | DF | Benno Schmitz | 1. FC Köln | Transfer | Summer | €1,500,000 | ||
| 22 | GK | Philipp Köhn | RB Salzburg | Transfer | Summer | Undisclosed | ||
| 24 | MF | Dominik Kaiser | Brøndby IF | Transfer | Summer | Free | ||
| — | MF | Elias Abouchabaka | Greuther Fürth | Loan | Summer | Free | ||
| – | MF | Felix Beiersdorf | ZFC Meuselwitz | Loan | Summer | Free | ||
| — | FW | Omer Damari | Hapoel Tel Aviv | Transfer | Summer | Free | ||
| — | FW | Agyemang Diawusie | Ingolstadt 04 | Transfer | Summer | €500,000 | ||
| — | MF | Vitaly Janelt | VfL Bochum | Transfer | Summer | Undisclosed | ||
| — | DF | Anthony Jung | Brøndby IF | Transfer | Summer | €800,000 | ||
| — | MF | Zsolt Kalmár | Dunajská Streda | Transfer | Summer | Undisclosed |
See main article: 2018–19 Bundesliga.
See main article: 2018–19 DFB-Pokal.
See main article: 2018–19 UEFA Europa League.
|-! colspan=14 style=background:#dcdcdc; text-align:center| Goalkeepers|-! colspan=14 style=background:#dcdcdc; text-align:center| Defenders|-! colspan=14 style=background:#dcdcdc; text-align:center| Midfielders|-! colspan=14 style=background:#dcdcdc; text-align:center| Forwards|-! colspan=14 style=background:#dcdcdc; text-align:center| Players transferred out during the season|-