- How I Met Your Mother S03E01 – Wait for it
- How I Met Your Mother S03E02 – We’re Not from Here
- How I Met Your Mother S03E03 – Third Wheel
- How I Met Your Mother S03E04 – Little Boys
- How I Met Your Mother S03E05 – How I Met Everyone Else
- How I Met Your Mother S03E06 – I’m Not That Guy
- How I Met Your Mother S03E07 – Dowisetrepla
- How I Met Your Mother S03E08 – Spoiler Alert
- How I Met Your Mother S03E09 – Slapsgiving
- How I Met Your Mother S03E10 – The Yips
- How I Met Your Mother S03E11 – The Platinum Rule
- How I Met Your Mother S03E12 – No Tomorrow
- How I Met Your Mother S03E13 – Ten Sessions
- How I Met Your Mother S03E14 – The Bracket
- How I Met Your Mother S03E15 – The Chain of Screaming
- How I Met Your Mother S03E16 – Sandcastles in the Sand
- How I Met Your Mother S03E17 – The Goat
- How I Met Your Mother S03E18 – Rebound Bro
- How I Met Your Mother S03E19 – Everything Must Go
- How I Met Your Mother S03E20 – Miracles
Robin returns from a trip to Argentina and Ted must adjust to life as just her friend. Marshall and Lily decide to move out on their own, falling in love with a place they can't afford. Marshall learns of Lily's bad credit rating due to her compulsive shopping. Despite this, they are able to finally secure their dream apartment, only to discover it's in a bad location and more poorly constructed than they thought. Barney is slapped for the third time on Thanksgiving, which Marshall dubs "Slapsgiving." Ted explains how he met all his friends.
Ted tells his children that he met their mother through a story with her yellow umbrella. He finds the umbrella at a club and takes home after attending a St. Patrick's Day party where his future wife was, although they did not meet. Ted attempts to woo Stella (Sarah Chalke), a dermatologist he sees to remove an embarrassing tattoo. This culminates in a memorable "two-minute date," which incorporates small talk, dinner, a movie, coffee, two cab rides, and a goodnight kiss, all within two minutes. Robin sleeps with Barney after he comforts her following a break-up, which is followed by Ted's disapproval and decision to stop being friends with Barney. Meanwhile, an unknown woman begins to sabotage Barney's attempts to hook up. His saboteur is revealed to be Abby (Britney Spears), Stella's receptionist, with a vendetta against him for not calling her after they had sex.
In the season finale, after Ted and Barney get into separate car accidents and end up in the hospital, they renew their friendship. It is revealed that Barney has true feelings for Robin, while Ted proposes to Stella.