[6] One of the first songs they wrote was "Tegan Didn't Go To School Today", written by Sara and recorded by the pair on cassette tape.

[14] In 1999, they released their debut album, Under Feet Like Ours, as "Sara and Tegan", with producer Jared Kuemper.,[15] After listening to it, Elliot Roberts flew up from Los Angeles to meet them at the Starfish Room in Vancouver, British Columbia, and he offered them a record deal that same night.

Guests and collaborators on the album included Jason McGerr of Death Cab for Cutie, Matt Sharp of The Rentals (and previously Weezer), Hunter Burgan of AFI, and Kaki King.

[18] On October 26, 2009, Tegan and Sara released their sixth album, Sainthood, produced by Chris Walla and Howard Redekopp.

[20] Spin gave Sainthood four out of five stars and wrote, "Tegan and Sara's music may no longer be the stuff of teens, but its strength remains in how much it feels like two people talking.

The album was released on January 29, 2013, and debuted on the Billboard Top 200 at number 3, the band's highest-charting record, selling 49,000 copies in its first week.

The participating artists recorded covers of The Con's original songs to benefit the Tegan and Sara Foundation.

[27] On September 24, 2019, their memoir High School was released by MCD Books, a division of Farrar, Straus, and Giroux, alongside Simon & Schuster Canada and Virago Press in the United Kingdom.

[28][29] The memoir details their teenage years, growing up in Canada and "worshipping" Nirvana, Green Day and the Smashing Pumpkins.

[31] On July 9, 2019, they announced via Instagram that their ninth album would be called Hey, I'm Just Like You and would consist of 12 re-recorded songs they initially wrote as teenagers.

In April 2020, the duo created a live "show" called Where Does the Good Grow to entertain their fans during the COVID-19 pandemic, with merchandise designed by EE Storey.

It explores the themes of growing up, coming out, and self-discovery through music and sisterhood (loosely serving as a prequel to their adolescence memoir, High School.

[45] Tegan and Sara have credited Green Day, Nirvana, and Hole for "truly start[ing] to cement our desire to write and make our music".

[47] Other artists who have influenced Tegan and Sara include Depeche Mode,[48][49] Rihanna,[50][51] Taylor Swift,[52] Madonna, Kate Bush, David Bowie, Mike Elizondo,[53] Pink, Lily Allen,[54] Erasure, Ace of Base,[55] Tom Petty, Britney Spears, Katy Perry,[56] Ani DiFranco, the New Pornographers, Cyndi Lauper, Sinéad O'Connor, Against Me!

[64] The sisters are cousins to musician Jen Twynn Payne, drummer and lead vocalist for the Vancouver-based band The Courtneys.

The sandwich featured "double chocolate" cookies and salted caramel ice cream and was named "Til Death Do Us Part".

The "Animals" T-shirt features Tegan and Sara, a turtle, fox, koala, penguin and a dragonfly, all labelled with their Latin names.

[70] In June 2014, Tegan and Sara joined WorldPride to perform in the closing ceremonies at Yonge–Dundas Square in downtown Toronto.

[73] In December 2016, in the wake of the United States presidential election, the sisters founded the Tegan and Sara Foundation to advocate for "economic justice, health and representation for LGBTQ girls and women".

[75] In 2024, Tegan and Sara began activism in response to new policy pitched by the United Conservative Party in Alberta.

[76] The Tegan and Sara Foundation published an open letter signed by more than 400 Canadian musicians denouncing the UCP policy.

Other notable touring mates include Ryan Adams, Weezer, Bryan Adams, Jack Johnson, the Black Keys, Ben Folds, Gogol Bordello, Cake, City and Colour, Death Cab for Cutie, Hot Hot Heat, the Killers, New Found Glory, Paramore, Rufus Wainwright, Eugene Francis Jnr, the Jezabels, An Horse, Steel Train, Holly Miranda and Speak.

In January 2014, Katy Perry announced that Tegan and Sara, Capital Cities, and Kacey Musgraves would be the opening acts for the North American leg of her Prismatic World Tour.

[84] Their 2016 tour for Love You to Death started in London and passed through Australia, Hong Kong, Singapore, and Taiwan in July before looping back to Canada and the United States.

In April 2008, Tegan wrote and recorded a song titled "His Love" at the request of Augusten Burroughs as a contribution to the audio version of his book A Wolf at the Table.

Sara sang backup vocals on two songs from former Smashing Pumpkins member James Iha's 2012 album Look to the Sky: "To Who Knows Where" and "Dream Tonight".

The shirt was designed by EE Storey, with all profits benefiting FIERCE NYC, an organization that builds the leadership and power of LGBTQ communities in New York City.

[92] They both feature on the single "Teenage Tears" with Arkells on the album Blink Twice [93] Their songs have been featured in the films Dallas Buyers Club, The Lego Movie, G.B.F., Monster-in-Law, Sweet November, These Girls and The Carmilla Movie and in the television shows Degrassi: The Next Generation, 90210, Being Erica, Ghost Whisperer, Grey's Anatomy, The Hills, Hollyoaks, jPod, The L Word, Life Unexpected, Melrose Place, One Tree Hill, Parenthood, Rookie Blue, The Vampire Diaries, Veronica Mars, Waterloo Road, What's New, Scooby-Doo?, Awkward, Riverdale, Girls, BoJack Horseman, and Scott Pilgrim Takes Off.

In 2011, Sara was a panellist on the CBC Radio One program Canada Reads, defending Jeff Lemire's graphic novel Essex County.

In 2016, the twins briefly appeared on Take My Wife, starring Cameron Esposito and River Butcher, through a particular YouTube-released holiday segment.