Direct proof of use
The public record for the Badr-3 launcher system in the 2023 Israel-Hamas War is strongest as recovered or captured materiel, not as a confirmed launch event. On November 17, 2023, the Israel Defense Forces said troops captured a Palestinian Islamic Jihad post in Gaza and removed two trucks of weapons that included Badr-3 surface-to-surface rocket parts. The same day, Times of Israel reported IDF claims that Israeli troops located Iran-made Badr-3 rockets, drones, and other weapons at an Islamic Jihad outpost in northern Gaza.
Army Recognition later described the discovery as an Iranian-origin Badr-3 Rocket Launcher System uncovered in Gaza during a targeted IDF operation. Taken together, the cited sources support the system's appearance in the war as PIJ-linked rocket-launch equipment and associated Badr-3 rockets or parts found by Israeli forces in Gaza.
Sources: IDF troops destroy major weapons production post in Gaza, Times of Israel IDF troops raid terror sites in Gaza, Israeli Army captures Iranian Badr-3 Rocket Launcher System in Gaza
Narrative
The Badr-3 is tied most closely to Palestinian Islamic Jihad. METIS describes the Badr-3 as a large-calibre, Gazan-produced PIJ artillery rocket, while The Iran Primer says PIJ extensively used the Badr-3 during the 2021 fighting and struck Ashkelon and Netivot with it. That pre-2023 service history explains why the 2023 Gaza discoveries are cataloged under Hamas and Gaza-based armed groups even though the specific sites described by IDF-linked reporting were PIJ outposts or production positions.
The war-specific evidence should be read narrowly. The cited November 2023 reports document discovery, capture, or recovery of Badr-3 launcher-related equipment, rockets, and parts in Gaza. They do not establish a specific Badr-3 firing incident during the 2023 Israel-Hamas War, nor do they identify a complete operational firing battery in service at a named launch site.
Sources: Badr 3 Rocket METIS, Iran Transfers Rockets to Palestinian Groups, IDF troops destroy major weapons production post in Gaza, Times of Israel IDF troops raid terror sites in Gaza