| Thomas Sommer Arnoldsen | |
| Nationality: | Danish |
| Birth Date: | 11 January 2002 |
| Height: | 1.94 m |
| Position: | Centre/Left back |
| Currentclub: | Aalborg Håndbold |
| Clubnumber: | 7 |
| Youthyears1: | –2020 |
| Youthclubs1: | Skanderborg Aarhus Håndbold |
| Years1: | 2020–2023 |
| Clubs1: | Skanderborg Aarhus Håndbold |
| Years2: | 2023– |
| Clubs2: | Aalborg Håndbold |
| Nationalyears1: | 2023– |
| Nationalteam1: | Denmark |
| Nationalcaps1: | 11 |
| Nationalgoals1: | 37 |
Thomas Sommer Arnoldsen (born 11 January 2002) is a Danish handball player for Aalborg Håndbold and the Danish national team.[1]
He represented Denmark at the 2022 European Under-20 Championship[2] and the 2023 Junior World Championship.