| | | |
| May 18, 2021 | L | Houston Apollos 1 at Sioux City Explorers 6 | Final |
| May 19, 2021 | L | Houston Apollos 2 at Sioux City Explorers 7 | Final |
| May 20, 2021 | L | Houston Apollos 0 at Sioux City Explorers 10 | Final |
| May 21, 2021 | W | Houston Apollos 6 at Gary SouthShore Railcats 4 | Final |
| May 22, 2021 | L | Houston Apollos 3 at Gary SouthShore Railcats 4 | Final (13) |
| May 23, 2021 | L | Houston Apollos 2 at Gary SouthShore Railcats 11 | Final |
| May 25, 2021 | L | Houston Apollos 7 at Sioux Falls Canaries 8 | Final |
| May 26, 2021 | L | Houston Apollos 0 at Sioux Falls Canaries 16 | Final |
| May 27, 2021 | | Houston Apollos at Sioux Falls Canaries | Ppd. |
| May 28, 2021 | L | Houston Apollos 4 at Fargo-Moorhead RedHawks 5 | Final |
| May 29, 2021 | L | Houston Apollos 1 at Fargo-Moorhead RedHawks 4 | Final |
| May 30, 2021 | L | Houston Apollos 3 at Fargo-Moorhead RedHawks 11 | Final |
| June 1, 2021 | W | Houston Apollos 6 at Cleburne Railroaders 4 | Final |
| June 2, 2021 | L | Houston Apollos 3 at Cleburne Railroaders 5 | Final |
| June 3, 2021 | L | Houston Apollos 5 at Cleburne Railroaders 6 | Final |
| June 4, 2021 | L | Houston Apollos 6 at Sioux Falls Canaries 18 | Final |
| June 5, 2021 | L | Houston Apollos 3 at Sioux Falls Canaries 15 (Game 1) | Final |
| June 5, 2021 | W | Houston Apollos 12 at Sioux Falls Canaries 11 (Game 2) | Final |
| June 6, 2021 | L | Houston Apollos 7 at Sioux Falls Canaries 16 | Final |
| June 8, 2021 | L | Houston Apollos 1 at Lincoln Saltdogs 10 | Final |
| June 9, 2021 | W | Houston Apollos 5 at Lincoln Saltdogs 4 | Final |
| June 10, 2021 | L | Houston Apollos 2 at Lincoln Saltdogs 4 | Final |
| June 11, 2021 | | Houston Apollos at Kansas City Monarchs | Ppd. |
| June 12, 2021 | L | Houston Apollos 2 at Kansas City Monarchs 7 (Game 1) | Final |
| June 12, 2021 | L | Houston Apollos 4 at Kansas City Monarchs 8 (Game 2) | Final |
| June 13, 2021 | L | Houston Apollos 5 at Kansas City Monarchs 11 | Final |
| June 15, 2021 | L | Houston Apollos 6 at Lincoln Saltdogs 7 | Final |
| June 16, 2021 | L | Houston Apollos 2 at Lincoln Saltdogs 3 | Final |
| June 17, 2021 | L | Houston Apollos 5 at Lincoln Saltdogs 8 | Final |
| June 18, 2021 | L | Houston Apollos 0 at Cleburne Railroaders 5 | Final |
| June 19, 2021 | L | Houston Apollos 5 at Cleburne Railroaders 6 | Final |
| June 20, 2021 | L | Houston Apollos 4 at Cleburne Railroaders 7 | Final |
| June 22, 2021 | W | Houston Apollos 10 at Sioux Falls Canaries 7 | Final |
| June 23, 2021 | L | Houston Apollos 3 at Sioux Falls Canaries 12 | Final |
| June 24, 2021 | L | Houston Apollos 7 at Sioux Falls Canaries 12 | Final |
| June 25, 2021 | L | Houston Apollos 7 at Winnipeg Goldeyes 13 | Final |
| June 26, 2021 | W | Houston Apollos 15 at Winnipeg Goldeyes 11 (Game 1) | Final |
| June 26, 2021 | L | Houston Apollos 1 at Winnipeg Goldeyes 6 (Game 2) | Final |
| June 29, 2021 | L | Houston Apollos 0 at Sioux City Explorers 3 | Final |
| June 30, 2021 | W | Houston Apollos 4 at Sioux City Explorers 3 | Final |
| July 1, 2021 | L | Houston Apollos 3 at Sioux City Explorers 5 | Final |
| July 2, 2021 | L | Houston Apollos 3 at Chicago Dogs 5 | Final |
| July 3, 2021 | L | Houston Apollos 2 at Chicago Dogs 8 | Final |
| July 4, 2021 | L | Houston Apollos 2 at Chicago Dogs 8 | Final |
| July 6, 2021 | L | Houston Apollos 0 at Kane County Cougars 3 | Final |
| July 7, 2021 | L | Houston Apollos 2 at Kane County Cougars 11 | Final |
| July 8, 2021 | L | Houston Apollos 1 at Kane County Cougars 2 | Final |
| July 9, 2021 | L | Houston Apollos 4 at Milwaukee Milkmen 5 | Final |
| July 10, 2021 | L | Houston Apollos 2 at Milwaukee Milkmen 3 | Final |
| July 11, 2021 | L | Houston Apollos 2 at Milwaukee Milkmen 3 | Final |
| July 13, 2021 | L | Houston Apollos 8 at Kansas City Monarchs 10 | Final |
| July 14, 2021 | L | Houston Apollos 11 at Kansas City Monarchs 12 | Final |
| July 15, 2021 | | Houston Apollos at Kansas City Monarchs | Ppd. |
| July 16, 2021 | L | Houston Apollos 4 at Chicago Dogs 13 | Final |
| July 17, 2021 | L | Houston Apollos 1 at Chicago Dogs 6 | Final |
| July 18, 2021 | L | Houston Apollos 4 at Chicago Dogs 6 | Final |
| July 21, 2021 | L | Houston Apollos 4 at Winnipeg Goldeyes 8 (Game 1) | Final |
| July 21, 2021 | L | Houston Apollos 4 at Winnipeg Goldeyes 5 (Game 2) | Final |
| July 22, 2021 | W | Houston Apollos 6 at Winnipeg Goldeyes 4 | Final |
| July 23, 2021 | L | Houston Apollos 5 at Sioux City Explorers 6 | Final |
| July 24, 2021 | L | Houston Apollos 3 at Sioux City Explorers 6 | Final |
| July 25, 2021 | L | Houston Apollos 4 at Sioux City Explorers 16 | Final |
| July 26, 2021 | L | Houston Apollos 6 at Kansas City Monarchs 15 | Final |
| July 27, 2021 | L | Houston Apollos 2 at Kansas City Monarchs 6 | Final |
| July 28, 2021 | L | Houston Apollos 1 at Kansas City Monarchs 12 (Game 1) | Final |
| July 28, 2021 | L | Houston Apollos 2 at Kansas City Monarchs 10 (Game 2) | Final |
| July 29, 2021 | L | Houston Apollos 6 at Kansas City Monarchs 10 | Final |
| July 30, 2021 | L | Houston Apollos 3 at Cleburne Railroaders 16 | Final |
| July 31, 2021 | W | Houston Apollos 6 at Cleburne Railroaders 0 | Final |
| August 1, 2021 | L | Houston Apollos 5 at Cleburne Railroaders 9 | Final |
| August 3, 2021 | L | Houston Apollos 1 at Lincoln Saltdogs 2 | Final |
| August 4, 2021 | L | Houston Apollos 4 at Lincoln Saltdogs 5 | Final |
| August 5, 2021 | W | Houston Apollos 9 at Lincoln Saltdogs 5 | Final |
| August 6, 2021 | L | Houston Apollos 3 at Kane County Cougars 15 | Final |
| August 7, 2021 | L | Houston Apollos 2 at Kane County Cougars 3 | Final |
| August 8, 2021 | L | Houston Apollos 10 at Kane County Cougars 17 | Final |
| August 10, 2021 | | Houston Apollos at Gary SouthShore Railcats | Susp. |
| August 11, 2021 | L | Houston Apollos 9 at Gary SouthShore Railcats 13 (Game 1) | Final |
| August 11, 2021 | W | Houston Apollos 4 at Gary SouthShore Railcats 1 (Game 2) | Final |
| August 12, 2021 | W | Houston Apollos 12 at Gary SouthShore Railcats 10 | Final |
| August 13, 2021 | L | Houston Apollos 1 at Milwaukee Milkmen 6 | Final |
| August 14, 2021 | L | Houston Apollos 1 at Milwaukee Milkmen 4 | Final |
| August 15, 2021 | L | Houston Apollos 2 at Milwaukee Milkmen 6 | Final |
| August 16, 2021 | L | Houston Apollos 3 at Sioux Falls Canaries 6 | Final |
| August 17, 2021 | L | Houston Apollos 6 at Sioux Falls Canaries 8 | Final |
| August 18, 2021 | W | Houston Apollos 10 at Sioux Falls Canaries 7 | Final |
| August 19, 2021 | L | Houston Apollos 1 at Sioux Falls Canaries 9 | Final |
| August 20, 2021 | L | Houston Apollos 1 at Fargo-Moorhead RedHawks 15 | Final |
| August 21, 2021 | L | Houston Apollos 2 at Fargo-Moorhead RedHawks 8 | Final |
| August 22, 2021 | L | Houston Apollos 11 at Fargo-Moorhead RedHawks 13 | Final |
| August 24, 2021 | L | Houston Apollos 2 at Sioux City Explorers 3 | Final |
| August 25, 2021 | W | Houston Apollos 9 at Sioux City Explorers 7 | Final |
| August 26, 2021 | W | Houston Apollos 8 at Sioux City Explorers 4 | Final |
| August 27, 2021 | L | Houston Apollos 3 at Kansas City Monarchs 6 | Final |
| August 28, 2021 | L | Houston Apollos 1 at Kansas City Monarchs 8 | Final |
| August 29, 2021 | L | Houston Apollos 0 at Kansas City Monarchs 2 | Final |
| August 30, 2021 | L | Houston Apollos 2 at Cleburne Railroaders 8 | Final |
| August 31, 2021 | L | Houston Apollos 4 at Cleburne Railroaders 12 | Final |
| September 1, 2021 | L | Houston Apollos 2 at Cleburne Railroaders 5 | Final |
| September 2, 2021 | L | Houston Apollos 3 at Cleburne Railroaders 6 | Final |
| September 3, 2021 | L | Houston Apollos 7 at Lincoln Saltdogs 18 | Final |
| September 5, 2021 | W | Houston Apollos 8 at Lincoln Saltdogs 6 (Game 1) | Final |
| September 5, 2021 | L | Houston Apollos 1 at Lincoln Saltdogs 3 (Game 2) | Final |
| September 6, 2021 | W | Houston Apollos 2 at Lincoln Saltdogs 0 | Final |
Houston Apollos Schedule
