T & A; relationship with McMahon (2000–2001):
Stratigias made her debut as a heel on the March 19, 2000 episode of Sunday Night Heat, under the ring name Trish Stratus. She appeared on stage to scout WWF Superstars, in particular Test and Prince Albert. The next night on Raw Stratus began her first role in the company, managing Test and Albert in the tag team T & A. It was during her stint managing T & A that Stratus took her first major bump in the ring, being driven through a table by the Dudley Boyz at Backlash after she had been taunting Bubba Ray Dudley for several weeks. She also began managing then-heel, Val Venis to win the Intercontinental Championship but their partnership ended at SummerSlam after Venis lost the title.
Stratus made her in-ring debut on the June 20 taping of SmackDown!, winning a tag team match with T & A against the Hardy Boyz and the face gimmick of Lita. A storyline feud between Stratus and Lita developed after the match with Stratus attacking Lita on episodes of Raw and SmackDown!, leading to an Indian Strap match on the July 24 edition of Raw which Stratus won with help from Stephanie McMahon. She finished the year competing unsuccessfully for the WWF Women's Championship numerous times, and leaving Test and Albert when the team disbanded.
In early 2001, Stratus became involved in an angle with WWF Chairman Vince McMahon, during a time when Vince's wife Linda was kayfabe institutionalized following a demand Vince had made for a divorce during an episode of SmackDown! on December 7, 2000. Vince and Stratus' relationship increasingly angered the boss' daughter, then-heel, Stephanie McMahon. At No Way Out on February 25, Stratus and Stephanie squared off, with Stephanie scoring the victory after a run-in by William Regal. In the midst of a tag team match that pitted Vince and Stratus against Regal and Stephanie the next night on Raw, Stratus was the victim of a set-up by Vince, Stephanie and Regal. Regal executed his finisher, the Regal Cutter, on Stratus and Stephanie then dumped sewage over Stratus' body. Vince stood over Stratus, and he told her she was a toy with which he had grown tired of playing and that it was over. The angle continued the next week on Raw with Vince forcing Stratus to strip down to her black underwear in the ring and bark like a dog. The storyline came to an end at WrestleMania X-Seven when Stratus slapped Vince during his match against his son Shane, becoming a fan favorite in the process.

Stratus then began wrestling part-time. She won a Bra and Panties tag team match with Lita against then-heels, Stacy Keibler and Torrie Wilson at InVasion. After suffering an ankle injury in the summer, however, she was sidelined for three months. As she rehabilitated, she kept herself visible by co-hosting Excess on TNN. After returning in autumn, Stratus appeared at Survivor Series where she won the WWF Women's Championship for the first time in a six-pack challenge. Stratus was next involved in a feud with Jazz over the Women's Championship, where she was booked to retain the title at the Royal Rumble but being booked to lose the belt to Jazz two weeks later on the February 4, 2002 edition of Raw. Stratus then went after the title for several months, even competing in a Triple Threat match at WrestleMania X8 against Lita and Jazz in her hometown of Toronto, Canada but failed to win the match. While chasing after the Women's title, Stratus won the WWE Hardcore Championship on May 6, pinning Crash Holly after Bubba Ray Dudley hit him over the head with a trash can. She, however, lost the title to then-heel, Steven Richards soon afterward due to the stipulation that the belt was defended 24/7 as long as there was a referee present. One week later, she regained the Women's Title in a tag team match with Bubba Ray Dudley. During this time, Stratus began wrestling solely on the Raw brand after being drafted in the WWF Brand Extension.
Stratus' second reign as champion came to an end on June 23 when she was defeated at King of the Ring by the heel gimmick of Molly Holly. The two Divas continued their storyline feud for the next three months. After a failed attempt to win the title in July, Stratus won back the championship at Unforgiven. While feuding with Holly, Stratus was also involved in an angle with new Diva the heel gimmick of Victoria who held a storyline grudge against Stratus, claiming she was betrayed by Stratus when they worked as fitness models. The two competed in several title matches, with Stratus retaining until Survivor Series where Victoria won the belt in a Hardcore match. On March 17, 2003, Victoria and Steven Richards defeated Jazz and Stratus in tag team competition. After the match, Jeff Hardy saved Stratus from an attack by both Victoria and Richards and kissed her. In the following weeks, Stratus and Hardy were shown talking backstage and fighting as tag team partners and Stratus became the on-screen girlfriend of Hardy. The storyline, however, was dropped when Hardy was released from WWE.
At WrestleMania XIX Stratus defeated Victoria and then-heel, Jazz to capture her fourth Women's Championship, equaling the record previously set by The Fabulous Moolah, only to lose the title to Jazz at the following pay-per-view, Backlash. In the following months, Stratus was placed into an alliance with Gail Kim. It was short-lived, though, as Kim turned on Stratus and teamed with Molly Holly, putting the women in a storyline feud. The duo defeated Stratus and several tag team partners until Stratus began to partner with a returning Lita. The team defeated Kim and Holly in several matches, including a match at Unforgiven.

Stratus began a romance with Chris Jericho during the November 10 edition of Raw when she agreed to go on a date with him. Subsequently, they participated in an intergender tag team match as partners on December 1. After the match, Stratus overheard Jericho talking to then-heel, Christian, who was involved in an on-screen romance with the face gimmick of Lita at the time, about who could sleep with their respective woman first. One week later, Stratus and Lita confronted the men about their actions, leading to a feud between the two men and women which resulted in a "Battle of the Sexes" match at Armageddon, which the women lost. A rematch the next night ended in a no contest. Her relationship with Jericho continued into the next year with a new angle of Jericho developing feelings for Stratus. Christian would also briefly turn face once again, but would quickly turn heel once more by doing a one night betrayal on Stratus and starting a feud with Jericho. During a match at WrestleMania XX, however, Stratus became a villain for the first time since her debut by betraying Jericho and siding with Christian, Stratus claimed her reasons for siding with Christian were that he was a real man and Jericho was a love sick puppy. The duo feuded with Jericho for several months and competed in a Handicap match at Backlash. The team of Stratus and Christian were joined by "problem solver" Tyson Tomko the next night on Raw.
Stratus was booked to win the Women's Championship for a fifth time at Bad Blood on June 13. She defended the title until she suffered a legitimate broken hand in July that caused her to be out of action for approximately a month. Upon her return, she continued to defend the title against numerous challengers before losing the championship to Lita on December 6 when both women wrestled in the main event of Raw for the championship. Stratus recaptured the gold a month later at New Year's Revolution after Lita suffered a legitimate injury during the match. A new angle was then developed between Stratus and 2004 Raw Diva Search winner Christy Hemme over jealousy of Hemme's Playboy magazine exposure, with Stratus attacking Hemme and spray painting the word "slut" across her back. Stratus was challenged by Hemme, who later revealed she was being trained by Lita, for a title match at WrestleMania 21 and was successful in retaining the title.

In May 2005 Stratus was sidelined with the Women's Championship after suffering a herniated disc, with the storyline explanation that Viscera had injured her with a big splash move at Backlash after she berated him for losing to Lita's then-husband Kane. She returned to Raw in September, once again portraying her face persona by siding with Ashley Massaro against Vince's Devils. The feud also involved the debuting Diva Mickie James who introduced herself as Stratus' biggest fan. On the Eddie Guerrero Tribute Show, Stratus took part in an interpromotional Diva battle royal that was won by SmackDown! Diva Melina. The next week, MNM kidnapped Stratus for Melina, who challenged a tied up and gagged Stratus to a match for the Women's Championship. The two fought at Survivor Series, with Stratus defeating Melina after interference from Mickie James. Stratus and James continued teaming together in late 2005 while James' character became increasingly obsessed with Stratus. On the December 26 episode of Raw, the storyline between Stratus and James developed into a lesbian one when James initiated an intimate kiss with Stratus under a sprig of mistletoe, causing a surprised Stratus to flee the locker room.
The odd relationship between Stratus and James continued into 2006, with the two Divas competing against each other in a title match at New Year's Revolution, where Stratus emerged victorious. Despite the defeat, James continued to be enamored of Stratus which made her feel uncomfortable. On March 6, 2006 Stratus confronted James, telling her that she needed space. The duo briefly reconciled on the March 18 edition of Saturday Night's Main Event, teaming together to defeat Candice Michelle and Victoria. James, however, turned on Stratus after the match and began to attack her. A match at WrestleMania 22 saw Stratus lose the Women's Championship to James. During a rematch at Backlash Stratus suffered a legitimate dislocated shoulder after taking a bump to the outside of the ring. While she was rehabilitating for six weeks she continued to appear on-screen.
Stratus returned to the ring on June 26 and started a romantic angle with Carlito after he saved her from a double team attack by Melina and Johnny Nitro. They competed as a team and won a mixed tag team match against Melina and Nitro at Saturday Night's Main Event on July 15. As a couple, Stratus and Carlito briefly feuded with WWE Champion Edge and Lita after the pair interrupted Stratus' title match with Mickie James. The two couples competed in several tag team matches, with Stratus and Carlito losing to Edge and Lita each time. In late August, Lita stated that Stratus would retire following Unforgiven, which was later confirmed by Stratus. At the pay-per-view on September 17, in her hometown of Toronto, Stratus defeated Lita with fellow Canadian Bret Hart's signature submission maneuver, the Sharpshooter, to win a record 7th Women's Championship and retire as champion.

Stratus made a special appearance on December 10, 2007 during Raw's 15th Anniversary special along with Lita, interrupting Jillian Hall as she sang by attacking her and then celebrating with Lita. Stratus made another special appearance on the May 5, 2008 episode of Raw, as the event took place from her hometown, Toronto, Ontario, Canada. She took part in a backstage segment involving Ron Simmons and Trevor Murdoch. Stratus wrestled her first match in over two years on the December 22, 2008 episode of Raw. She and John Cena defeated Santino Marella and her former on-screen protégé Beth Phoenix in a mixed tag team match. Stratus also served as the guest hostess of the September 14, 2009 edition Raw in her home town of Toronto. After a confrontation backstage with Phoenix and former character beau Chris Jericho, she participated in what would be a six-person tag team match with MVP and Mark Henry to defeat Phoenix, Jericho, and The Big Show.