Strahan was born in Houston, Texas. He is the son of Louise (Traylor) Strahan, a basketball coach, and Gene Willie Strahan, a boxer with a 1-1 record against future heavyweight Ken Norton. He is the nephew of retired pro football player Arthur Strahan. He is the youngest of 6 children. Gene was a major in the U.S. Army, and when Michael was 9, the Strahans moved to an army post - BFV (Benjamin Franklin Village) - in Mannheim, West Germany. Although Strahan did not begin to play high school football at Westbury High School (Houston, Texas) until his senior year, he did play organized football while attending school at MAHS (Mannheim American High School) a US Department of Defense Dependent High School, in Kafertal (Mannheim), Germany, playing linebacker for the Mannheim Redskins in 1985. The summer before Strahan's senior year of high school, his father sent him to live with his uncle Art in Houston so he could attend Westbury High School. Strahan played one season of football, which was enough for him to get a scholarship offer from Texas Southern University. He then flew back to Germany for the spring term, where he graduated from Mannheim Christian.
Strahan followed in the footsteps of his uncle Art, who also played defensive end at Texas Southern University. Strahan was so dominant he drew double teams, and TSU coaches dubbed Strahan double teaming "Strahan rules." By his junior season, Strahan began to turn himself into an NFL prospect. As a senior at Texas Southern, Strahan was selected All-America first team by The Poor Man's Guide to the NFL Draft, The Sheridan Network, Edd Hayes Black College Sports Report and the Associated Press. He recorded 62 tackles with a school-record 19 quarterback sacks and 32 tackles totaling 142 yards in losses. He was also selected Division I-AA Defensive Player of the Year by The Poor Man's Guide and Edd Hayes Black College Sports Report. In 1992 he was named 1st team All-Southwestern Athletic Conference and the SWAC's Player of the Year for the 2nd consecutive season. He was also named Black College Defensive Player of the Year. As a junior in 1991, Strahan led the SWAC with 14.5 quarterback sacks. His 41.5 career sacks is a Texas Southern record.
Strahan was drafted by the New York Giants in 1993. He played in only 9 games due to injuries, and missed the Giants' two playoff games that season. After a few unremarkable seasons, Strahan had a breakout year in 1997, recording 14 sacks. He was voted into his first Pro Bowl and was also named First Team All-Pro by the Associated Press. In 1998, Strahan continued his success, racking up 15 sacks and being voted into his second Pro-Bowl and All-Pro team.
Strahan was a member of the 2000 Giants and participated in their playoff run to Super Bowl XXXV. Despite coming off a strong NFC Championship Game, where the Giants defeated the Minnesota Vikings 41–0, the Baltimore Ravens proved too strong for the Giants and they were handily defeated 34–7. In 2002, Michael Strahan and the Giants negotiated on a new contract. He said the team failed to negotiate after he turned down its first contract proposal. He accused the front office of not trying to be competitive in 2002. Four days later, running back Tiki Barber ripped him for being selfish and greedy. The two had a heated phone conversation that night, and Strahan said they no longer speak. It also surfaced in the spring that the Giants explored trading Strahan, after which he suggested that management had orchestrated the contract flap to make him look bad. The team denied that.
Few defensive ends in the NFL were more dominant than Strahan from 1997 to 2005. He was named the 2001 NFL Defensive Player of the Year and was a two-time NFC Defensive Player of the Year (in 2001 and 2003). Throughout the greater part of the 2004 season, Strahan was injured with a torn pectoral muscle, which limited him to only 4 sacks. He rebounded in 2005, returning to the Pro Bowl, with his protégé, Osi Umenyiora as the two combined for 26 sacks while anchoring the Giants' defense. Strahan was considered by many coaches, peers, and experts as the standard, and best at his position during the prime of his career (1997-2005). He was also regarded as one of if not the best defensive end ever at defending the run which made people and peers view him as a complete defensive end.
It looked as though Strahan would retire after the 2006 season when he did not report to Giants training camp and missed the entire preseason, but the 14-year veteran opted to return for one final year. On October 23, 2006, with a sack of Drew Bledsoe in a Monday night game against the Dallas Cowboys, Strahan tied Lawrence Taylor for the Giants franchise record for most career sacks with 132½. It was the last sack Strahan would get that season, as two weeks later he suffered a Lisfranc fracture against the Houston Texans and would miss the remainder of the season and the playoffs.
His 15th and final season proved to be the Giants' best season since 1990. On September 30, 2007, he sacked Donovan McNabb from the Philadelphia Eagles on Sunday Night Football, increasing his career total to 133.5, setting a new franchise record. This total does not include 9½ sacks accrued by Taylor in his rookie season of 1981, the year before sacks became an official NFL statistic. On Sunday February 3, 2008, at the University of Phoenix Stadium in Glendale, Arizona, Strahan had 2 tackles and 1 sack in Super Bowl XLII, in what is considered one of the biggest upsets in NFL history. Bolstered by a strong defense and unrelenting pass rush, the Giants went on to win the game 17-14, over the then-undefeated 18-0 New England Patriots, giving Strahan his first Super Bowl win as an NFL starter. His saying was "Stomp you out!"
On June 9, 2008, Strahan retired from the NFL. He told Jay Glazer of Foxsports.com "It's time, I'm done."
Strahan retired with a 2008 Super Bowl Title (his last game), 141.5 career sacks, 854 career tackles, 4 career interceptions, 24 forced fumbles and 3 career touchdowns in 200 games over a 15-year career (through 2007 season). He was also named to the Pro Bowl roster seven times.
Super Bowl XLVIII, played in East Rutherford, New Jersey, was dedicated to Strahan upon his induction into the Pro Football Hall of Fame in 2014. Strahan performed the ceremonial coin toss, accompanied by the other members of that year's PFHOF class. Strahan also commented on the trophy presentation for Fox, since Terry Bradshaw (who had commented on the trophy presentations for Fox's previous Super Bowl broadcasts) was mourning the death of his father. On November 3, 2014, he was presented his Hall of Fame ring at halftime of the New York Giants-Indianapolis Colts game by the Giants. In attendance were 100 former Giants players as well as former teammates of Strahan's.
In the 2001 season, Strahan set the NFL record for sacks in a single season with 22.5, the highest tally since it was made an official statistic in 1982, breaking New York Jets' Mark Gastineau's total of 22. In the final game of the season on January 6, 2002, with Strahan coming free, Packers quarterback Brett Favre slid down and Strahan fell on top of Favre for an easy sack. After the play, during the ensuing celebration, many of the Giants' defensive players patted Favre on the helmet. At least one observer accused Favre of deliberately falling to ensure that Strahan would get the record. However, Packers right tackle Mark Tauscher claimed it was just a bad play and "we wanted to avoid that sack."New York Times columnist Mike Freeman wrote, "Yes, Mr. Favre, Strahan deserves the record, but please, handing it to him the way you did, as if you were throwing change into a Salvation Army bucket, is the kind of mistake Favre may never live down."
On October 1, 2010, Strahan co-hosted Live! with Regis and Kelly with Kelly Ripa for the first time when Regis Philbin was absent for that show. Regis left in November 2011, leaving an empty spot. After twenty guest appearances over two years, Strahan was selected as Kelly Ripa's new co-host on September 4, 2012, marking his first official day on the rechristened syndicated talk show, Live! with Kelly and Michael. Ratings instantly surged, impressively generating year-over-year time slot gains across all key demographics, towering over its nearest competition, the fourth hour of NBC's Today Show, by 87 percent.
Strahan was married to his first wife, Wanda Hutchins, in Germany until 1996. They have a daughter, Tanita Strahan (b. 1992), and son, Michael Anthony Strahan, Jr. (b. 1995). Strahan then moved them to the US and purchased a $163,000 house in the same Houston neighborhood in which his parents reside.
In 1999, he married Jean Muggli of North Dakota after meeting at a Manhattan spa. They have twin daughters, Sophia and Isabella Strahan (b. 2004). They divorced acrimoniously in 2006. In January 2007 Judge James B. Cooney awarded Muggli $15 million in a divorce settlement in addition to $18,000 monthly child support. In her testimony, Muggli claimed that their (at the time 20-month-old) daughters liked "to be accessorized", and that "Isabella doesn't like to leave the house without a purse" and that the children's preferences justified her spending $22,500 on photo shoots, $27,000 on clothing, and $1,700 for sign language classes. (Neither daughter is hearing impaired.) With this being more than half of his $22 million in assets, Strahan appealed. In March 2007, divorce judge Cooney ordered the mansion to be auctioned and the sales money split evenly with Jean; the house is valued at $3.6 million.
In 2009 Strahan attached a GPS to track his girlfriend's car.
In 2002, he had a multimillion dollar restoration and renovation done  on Georgian Heights, a home built in 1906 at 99 Lloyd Ave Montclair, New Jersey, a red brick house with a carriage house and greenhouse that he bought in 2000 for $1.3 million. Before moving in he allowed the Junior League of Montclair-Newark to use his house as a model home for its Montclair Junior League show house charity fundraiser. From May 28–31, the League decorated the mansion, had a 'bare bones' party and a black-tie affair; they also held $25 tours  to fund Junior League programs called Children At Risk and HomeCorp. Children At Risk aids children and families  and HomeCorp is a housing agency that helps low income people achieve home ownership.
"Basically, we're redoing our house to let strangers walk through it for a month," Strahan said. "It's a month-long fundraiser. They'll come in and decorate, paint the walls. They'll hang the curtains, bring in furniture, light fixtures. None of it will be ours. When they're done, if we want something, we get it at cost."
In February 2008, Strahan and Giants teammate Justin Tuck teamed up with Nike to design their own exclusive pair of sneakers for ID studio in New York City. All proceeds of the sneakers were donated to Nike’s Let Me Play global campaign.