The ATP Challenger 125 tournaments are the second highest tier of annual men's tennis tournaments on the ATP Challenger Tour, with 125 ranking points awarded to each singles champion. They were previously the highest tier of Challenger tournaments before the introduction of ATP Challenger Tour 175 tournaments in 2023.
As of the last full season in 2019, the series included 20 tournaments, however more have since been added as a result of the COVID-19 pandemic.
| Tournament | Officially known as | City | Country | Surface | |
|---|---|---|---|---|---|
| Canberra | Canberra Challenger | Canberra |  Australia | Hard | |
| Istanbul | Amex-Istanbul Challenger | Istanbul |  Turkey | Hard | |
| Newport Beach | Oracle Challenger Series – Newport Beach | Newport Beach |  United States | Hard | |
| Bangalore | Bengaluru Open | Bangalore |  India | Hard | |
| Biella 2 | Biella Challenger Indoor II | Biella |  Italy | Hard (i) | |
| Nur-Sultan 2 | Nur-Sultan Challenger II | Nur-Sultan |  Kazakhstan | Hard (i) | |
| Indian Wells | Oracle Challenger Series – Indian Wells | Indian Wells | United States | Hard | |
| Mexico City | Mexico City Open | Mexico City |  Mexico | Clay | |
| Taipei | Santaizi ATP Challenger | Taipei City |  Taiwan | Hard (i) | |
| Anning | Kunming Open | Anning |  China | Clay | |
| Belgrade | Serbia Challenger Open | Belgrade |  Serbia | Clay | |
| Aix-en-Provence | Open du Pays d'Aix | Aix-en-Provence |  France | Clay | |
| Bordeaux | BNP Paribas Primrose Bordeaux | Bordeaux | France | Clay | |
| Busan | Busan Open | Busan |  South Korea | Hard | |
| Oeiras 3 | Open de Oeiras III | Oeiras | Portugal | Clay | |
| Surbiton | Surbiton Trophy | Surbiton |  United Kingdom | Grass | |
| Nottingham | Viking Open Nottingham | United Kingdom | Grass | ||
| Ilkley | Ilkley Trophy | United Kingdom | Grass | ||
| Salzburg | Salzburg Open | Anif/Salzburg |  Austria | Clay | |
| New Haven | Oracle Challenger Series – New Haven | New Haven | United States | Hard | |
| Jinan | Jinan International Open | Jinan | China | Hard | |
| Genoa | AON Open Challenger | Genoa | Italy | Clay | |
| Szczecin | Pekao Szczecin Open | Szczecin |  Poland | Clay | |
| Kaohsiung | OEC Kaohsiung | Kaohsiung City | Taiwan | Carpet (i) | |
| Orléans | Open d'Orléans | Orléans | France | Hard (i) | |
| Santo Domingo | Santo Domingo Open | Santo Domingo |  Dominican Republic | Clay | |
| Ningbo | Ningbo International Tennis Open | Ningbo | China | Hard | |
| Houston | Oracle Challenger Series – Houston | Houston | United States | Hard |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Men's singles[1] | 125 | 75 | 45 | 25 | 10 | 0 | 5 | 2 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Men's doubles | 0 |
| 2019 | 2020 | 2021 | 2022 | 2023 | |||||
|---|---|---|---|---|---|---|---|---|---|
| Canberra | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Kohlschreiber | Cancelled | Cancelled | bgcolor=#ececec colspan=1 align=center | Challenger 100 | ||
| Istanbul | bgcolor=#ececec colspan=1 align=center | Challenger 90 | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Rinderknech | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 75 |
| Newport Beach | Kwiatkowski | Cancelled | bgcolor=#ececec colspan=2 align=center | Not an event | |||||
| Quimper | bgcolor=#ececec colspan=2 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 100 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Barrère | ||
| Ottignies | bgcolor=#ececec colspan=4 align=center | Not an event |  Goffin | ||||||
| Manama | bgcolor=#ececec colspan=2 align=center | Not an event | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Not an event | Kokkinakis | ||
| Bangalore | bgcolor=#ececec colspan=1 align=center | Not an event | Duckworth | Cancelled | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 100 | |
| Biella 2 | bgcolor=#ececec colspan=2 align=center | Not an event | Kwon | bgcolor=#ececec colspan=2 align=center | Not an event | ||||
| Nur-Sultan 2 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Abandoned |  Macháč | bgcolor=#ececec colspan=2 align=center | Not an event | |||
| Indian Wells | Edmund | Johnson | Cancelled | bgcolor=#ececec colspan=2 align=center | Not an event | ||||
| Phoenix | Berrettini | Cancelled | Kudla | bgcolor=#ececec colspan=1 align=center | Challenger 175 | ||||
| Marbella | bgcolor=#ececec colspan=3 align=center | Challenger 80 |  Munar | bgcolor=#ececec colspan=1 align=center | Not an event | ||||
| Monterrey | Bublik | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Cancelled due to the COVID-19 pandemic | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Borges | ||
| Mexico City | bgcolor=#ececec colspan=1 align=center | Not an event | Cancelled due to the COVID-19 pandemic | Hüsler | Koepfer | ||||
| Taipei | Novak | bgcolor=#ececec colspan=2 align=center | Not an event | ||||||
| Anning | Clarke | bgcolor=#ececec colspan=2 align=center | Not an event | ||||||
| Pau | bgcolor=#ececec colspan=1 align=center | Challenger 90 | bgcolor=#ececec colspan=3 align=center | Challenger 100 | Van Assche | ||||
| Sanremo | bgcolor=#ececec colspan=3 align=center | Not an event | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Van Assche | ||||
| Belgrade | bgcolor=#ececec colspan=2 align=center | Not an event | Carballés Baena | bgcolor=#ececec colspan=2 align=center | Not an event | ||||
| Sarasota | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Cancelled | Cancelled | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Altmaier | ||
| Aix-en-Provence | Cuevas | Otte | Taberner | bgcolor=#ececec colspan=1 align=center | Challenger 100 | bgcolor=#ececec colspan=1 align=center | Challenger 175 | ||
| Bordeaux | bgcolor=#ececec colspan=1 align=center | Challenger 110 | Cancelled | Cancelled | Popyrin | bgcolor=#ececec colspan=1 align=center | Challenger 175 | ||
| Busan | Berankis | Majchrzak | Vukic | ||||||
| Oeiras 3 | bgcolor=#ececec colspan=2 align=center | Not an event | Alcaraz | bgcolor=#ececec colspan=1 align=center | Challenger 80 |  Piros | |||
| Seoul | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Cancelled | Cancelled | bgcolor=#ececec colspan=1 align=center | Challenger 110 | Yunchaokete | ||
| Forlì | bgcolor=#ececec colspan=1 align=center | Not an event | bgcolor=#ececec colspan=1 align=center | Challenger 100 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Musetti | bgcolor=#ececec colspan=1 align=center | Not an event |
| Heilbronn | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Cancelled | bgcolor=#ececec colspan=2 align=center | Challenger 100 | Arnaldi | |||
| Surbiton | Evans | Cancelled | Thompson | Murray | |||||
| Nottingham | Evans | Tiafoe | Evans | Murray | |||||
| Perugia | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Munar | Marozsán | |||
| Ilkley/Nottingham 2 | Koepfer | Bolt | Bergs | Kubler | |||||
| Parma | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Tiafoe | bgcolor=#ececec colspan=1 align=center | ATP Tour 250 | Ćorić | Müller | ||
| Anif/Salzburg | bgcolor=#ececec colspan=2 align=center | Not an event |  Bagnis |  Monteiro | Ofner | ||||
| Braunschweig | bgcolor=#ececec colspan=1 align=center | Challenger 90 | Cancelled | bgcolor=#ececec colspan=1 align=center | Challenger 90 | Struff | Agamenone | ||
| Zug | bgcolor=#ececec colspan=3 align=center | Not an event | Stricker | Rinderknech | |||||
| Porto | bgcolor=#ececec colspan=2 align=center | Not an event | bgcolor=#ececec colspan=2 align=center | Challenger 80 | Nardi | ||||
| San Marino | bgcolor=#ececec colspan=2 align=center | Not an event | bgcolor=#ececec colspan=2 align=center | Challenger 90 | Munar | ||||
| Santo Domingo |  Varillas | Cancelled | Cancelled | Cachin | Olivieri | ||||
| Vancouver | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Lestienne | bgcolor=#ececec colspan=1 align=center | Not an event | ||||
| Stanford | bgcolor=#ececec colspan=4 align=center | Not an event | Lestienne | ||||||
| Prague | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Wawrinka | bgcolor=#ececec colspan=2 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 75 | ||
| Prague 2 | bgcolor=#ececec colspan=1 align=center | Not an event |  Karatsev | bgcolor=#ececec colspan=3 align=center | Challenger 50 | ||||
| Ostrava | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Karatsev | bgcolor=#ececec colspan=2 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 75 | ||
| Prostějov | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Majchrzak | bgcolor=#ececec colspan=3 align=center | Challenger 100 | ||||
| New Haven | Paul | Cancelled | Cancelled | bgcolor=#ececec colspan=2 align=center | Not an event | ||||
| Jinan | Zhang | bgcolor=#ececec colspan=2 align=center | Not an event | ||||||
| Genoa | Sonego | Monteiro | Seyboth Wild | ||||||
| Seville | bgcolor=#ececec colspan=1 align=center | Challenger 90 | bgcolor=#ececec colspan=2 align=center | Challenger 90 | Carballés Baena | ||||
| Szczecin |  Kovalík | Kolář | Moutet | Coria | |||||
| Kaohsiung | Millman | Cancelled | bgcolor=#ececec colspan=2 align=center | Not an event | |||||
| Bad Waltersdorf | bgcolor=#ececec colspan=4 align=center | Not an event | Pellegrino | ||||||
| Saint-Tropez | bgcolor=#ececec colspan=2 align=center | Not an event | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 100 | Lestienne | ||
| Orléans |  Ymer | Cancelled | Laaksonen | Barrère | Macháč | ||||
| Bogotá | bgcolor=#ececec colspan=4 align=center | Not an event | Tirante | ||||||
| Parma 2 | bgcolor=#ececec colspan=3 align=center | Not an event | Skatov | bgcolor=#ececec colspan=1 align=center | Not an event | ||||
| Bratislava | bgcolor=#ececec colspan=1 align=center | Challenger 110 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=2 align=center | Challenger 90 |  Diallo | ||
| Málaga | bgcolor=#ececec colspan=3 align=center | Not an event | bgcolor=#ececec colspan=1 align=center | Challenger 80 | Blanchet | ||||
| Olbia | bgcolor=#ececec colspan=4 align=center | Not an event | Jacquet | ||||||
| Ningbo |  Uchiyama | Cancelled | Cancelled | bgcolor=#ececec colspan=2 align=center | Not an event | ||||
| Houston | Giron | bgcolor=#ececec colspan=2 align=center | Not an event | ||||||
| Helsinki | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 80 | bgcolor=#ececec colspan=1 align=center | Challenger 90 |