| Season | Premiere | Episodes | Notable |
|---|---|---|---|
| Season 1 | May 2012 | 8 | Premiered May 31 with “Winter Is Coming” (HISTORY) |
| Season 2 | June 2013 | 16 | — |
| Season 3 | June 2014 | 16 (+1 special) | — |
| Season 4 | June 2015 | 16 (+1 special) | — |
| Season 5 | May 2016 | 16 (+1 special) | Premiere month differs by source: May 5 vs May 12 |
| Season 6 | June 2017 | 16 (+1 special) | — |
| Season 7 | July 2018 | 16 | — |
| Season 8 | June 2019 | 13 | — |
| Season 9 | June 2020 | 12 (+4 specials) | TMDB counts 16 total; Wikipedia separates specials |
| Season 10 | June 2021 | 10 | — |
| Season 11 | September 2022 | 13 | — |
| Season 12 | August 2023 | 10 (+8 specials) | TMDB counts 18 total; Wikipedia separates specials |
| Season 13 | October 2024 | 12 | Premiered October 3, 2024 (HISTORY) |
| Season 14 | September 2025 | 13 | Tom Oar's farewell season (HISTORY press release) |
| Season 15 | October 2026 | 3 aired by Oct 22, 2026 | In progress — episodes Oct 7, 14, 21; Oct 28 upcoming (HISTORY) |
Sources count regular episodes separately from specials where databases disagree. Season 15 is in progress — its count is episodes aired as of October 22, 2026.