During the 20th century, the NCAA had no playoff for the major college football teams in the University Division, later known as Division I-A and now known as Division I FBS. The NCAA did recognize a national champion based upon the final results of "wire service" (AP and UPI) polls. The extent of that recognition came in the form of acknowledgment in the annual NCAA Football Guide of the "unofficial" national champions. The AP poll in 1956 consisted of the votes of as many as 198 sportswriters. Though not all writers voted in every poll, each would give their opinion of the twenty best teams. Under a point system of 20 points for first place, 19 for second, etc., the "overall" ranking was determined. Although the rankings were based on the collective opinion of the representative sportswriters, the teams that remained "unbeaten and untied" were generally ranked higher than those that had not. A defeat, even against a strong opponent, tended to cause a team to drop in the rankings, and a team with two or more defeats was unlikely to remain in the Top 20.
On September 22, #1 Oklahoma and #2 Michigan State were idle. #3 Notre Dame lost in Dallas to unranked SMU, 19–13 and dropped out of the top 5 for the season (and finished 2–8), while SMU would rise to fifth. #4 Georgia Tech won at Kentucky, 14–6. #5 Ohio State, which had not started play, fell out of the Top 5 and was replaced by #7 TCU, which had opened with a 32–0 win at Kansas. The first regular AP poll was 1.Oklahoma 2.Georgia Tech 3.Michigan State, 4.TCU and 5.SMU.
September 29, #1 Oklahoma opened its season with a 36-0 win over North Carolina. In Dallas, #2 Georgia Tech visited #5 SMU and narrowly won 9–7. #3 Michigan State won 21–7 at #12 Stanford. #4 TCU was idle and dropped to 8th, while #8 Ohio State rose to 4th after a 34-7 win hosting Nebraska. #13 Michigan, which had beaten UCLA 42-13, rose to 5th. The next poll was 1.Oklahoma 2.Michigan State 3.Georgia Tech 4.Ohio State 5.Michigan.
October 6 #1 Oklahoma registered another shutout, beating Kansas State 66-0. #2 Michigan State met #5 Michigan in the rain before a crowd of 101,001 at Ann Arbor, and MSU Coach Duffy Daugherty's "umbrella defense" forced two Michigan turnovers that led to their 9-0 win #3 Georgia Tech was idle, and #4 Ohio State won 32-20 at home before 82,881 over Stanford. The poll saw Michigan drop to 12th, while #8 TCU (which beat Arkansas 41-6 on national television) returned to the top five: 1.Oklahoma 2.Michigan State 3.Georgia Tech 4.TCU 5.Ohio State
October 13 At Dallas, #1 Oklahoma beat Texas 45-0, having outscored its opposition 147-0 in three games. A commentator of the day wrote, "The overpowering charge of the big red-shirted Oklahoma line ahead of adroit Quarterback Jimmy Harris is just one of the reasons why Oklahoma may be the greatest college football team of all time... They showed it in the sudden, lifting charge of a line which moved all of a piece, like a wave breaking evenly along a beach."  #2 Michigan State defeated Indiana 53–6 at home. #3 Georgia Tech beat LSU, 39–7. #4 TCU won at Alabama 23–6, and #5 Ohio State won 26–6 at Illinois. The poll remained unchanged: 1.Oklahoma 2.Michigan State 3.Georgia Tech 4.TCU 5.Ohio State
October 20 #1 Oklahoma gave up its first points of the season, but registered its fourth win, 34-12, at Kansas. #2 Michigan State stayed unbeaten with a 47-14 win at Notre Dame. #3 Georgia Tech beat Auburn 28-7. In a game that would ultimately determine the SWC championship, #4 TCU lost at #14 Texas A&M, 7-6. #5 Ohio State lost to Penn State by the same 7-6 score. #7 Tennessee, which had beaten Alabama 24-0 rose to 4th, and #8 Michigan returned to the Top 5 after its 34-20 win over Northwestern. The poll: 1.Michigan State 2. Oklahoma 3.Georgia Tech 4.Tennessee 5.Michigan.
October 27 The new #1 Michigan State went to Champaign, and had a 13-0 lead over the unranked Illini at halftime. Abe Woodson plunged for a score to cut the lead to 13-6 after three quarters. In the fourth, Woodson ran 70 yards from scrimmage to help tie the game 13-13. After an MSU field goal was short, Woodson ran the ball up to the Illini 18. Woodson, who had once held the world record in the 50 yard high hurdles, took a short pass and dashed 82 yards for a touchdown, leaping over State's Art Johnson 30 yards from goal, to pull off the 20-13 upset. #2 Oklahoma was determined to prove itself number 1, and Coach Bud Wilkinson directed the team to six touchdowns for a 40-0 win at Notre Dame. #3 Georgia Tech beat #15 Tulane by the same 40-0 margin. #4 Tennessee beat Maryland 34-7 to stay unbeaten. #5 Michigan had its second loss, falling to unranked Minnesota at home, 20-7. #7 Texas A&M, which had extended its record to 5-0-1 with a 19-13 win at #8 Baylor, replaced the Wolverines. The poll: 1.Oklahoma 2.Georgia Tech 3.Tennessee 4.Michigan State 5.Texas A&M.
November 3 Unbeaten #1 Oklahoma (5–0), met the Colorado Buffaloes (5–1) on the road, and were losing 19–6 at halftime to a team that was four-touchdown underdog, but came back with touchdowns by Tommy McDonald and Clendon Thomas for a difficult 27-19 win. and the rest of top five won in shutouts: #2 Georgia Tech won 7–0 at Duke, #3 Tennessee over North Carolina 20-0, #4 Michigan State crushed Wisconsin 33-0, and #5 Texas A&M beat Arkansas 27-0. The poll remained unchanged.
While #1 Oklahoma registered its fifth shutout in seven games, trouncing Iowa State 44–0, #2 Georgia Tech and #3 Tennessee met in Atlanta for a game that proved to determine the SEC title. There were 23 punts altogether, and no score until midway through the third quarter, when Tennessee end Buddy Cruze noticed that Tech had stopped double-teaming him. Halfback Johnny Majors (who would later be head coach for UT) passed to Cruze at the 35-yard line, and Cruze ran 64 yards down to the Tech goal line, setting up the touchdown that won the game 6–0. In the poll that followed, Tennessee was the new #1 by a margin of 2 points (1,446 to 1,444) over Oklahoma. #4 Michigan State narrowly beat Purdue, 12-9. #5 Texas A&M beat SMU 33–7 in Dallas, and increased its record to 7-0-1, with the Southwest Conference title and a trip to the Cotton Bowl, and on November 12, was still fifth in the poll. Though on probation since 1955 for recruiting violations, the Aggies had appealed to the NCAA to allow them to play postseason. The next day, however, the NCAA announced that Texas A&M was still banned, because of an additional recruiting violation of a basketball player. The poll: 1.Tennessee 2.Oklahoma 3.Michigan State 4.Georgia Tech 5.Texas A&M.
November 17 #1 Tennessee beat visiting #19 Ole Miss 27-7, while #2 Oklahoma showed off its offense in crushing Missouri 67-14, sufficiently enough to regain the top spot in the next poll. #3 Michigan State traveled to Minnesota, which had been #6 a week before, but dropped to #17. The MSU visitors lost, 14-13, and dropped to tenth place in the next poll. #4 Georgia Tech beat Alabama 27-0. #5 Texas A&M beat visiting Rice, 21-7. #7 Iowa, which had beaten #6 Ohio State 6-0, took Michigan State's place in the poll that followed. The Top 5 was 1.Oklahoma 2.Tennessee 3.Iowa 4.Texas A&M 5.Georgia Tech.
November 24 #1 Oklahoma gained 656 net yards in a defeat of visiting Nebraska 54-6. #2 Tennessee beat Kentucky 20-7. #3 Iowa, which had captured the Big Ten title with a 5–1 conference record, finished its season with a 48–8 non-league win over Notre Dame, then accepted a bid to the Rose Bowl to play Oregon State. #4 Texas A&M was idle as it prepared for its Thanksgiving Day game with Texas, which it won 34–21. In Jacksonville, #5 Georgia Tech beat #13 Florida 28–0, and traded places with A&M. Tech would be invited back to the city for the Gator Bowl at season's end. The poll: 1.Oklahoma 2.Tennessee 3.Iowa 4.Georgia Tech 5.Texas A&M.
December 1 #1 Oklahoma closed its season with a 53–0 win over Oklahoma State, finishing 10–0, and with a 466–51 finish in points. Only one of its ten opponents (Colorado) finished 1956 with a winning record. In Nashville, #2 Tennessee beat Vanderbilt 27–7 to close with a 10–0 record and a spot in the Sugar Bowl, where it would face 9–1 Baylor. #4 Georgia Tech closed with a 35–0 win at Georgia. Unbeaten and once-tied (9-0-1), #5 Texas A&M won the Southwest Conference title, but the ban against post-season play sent runner-up TCU to the Cotton Bowl instead.