Rodney McKay's sister, Jeannie Miller is played by Kate Hewlett who is David Hewlett's sister in real life.

During the first season and much of the second, most of the Wraith males were played by the same actor: James Lafazanos.

Paul McGillion (Dr. Carson Beckett) was also in Stargate SG-1: The Torment of Tantalus (1997) as the young Ernest Littlefield.

Joe Flanigan (John Sheppard) and David Hewlett (Rodney McKay) are the only actors to appear in all 100 episodes. Rachel Luttrell (Teyla Emmagan) is the only other regular cast member to stay with the series throughout its entire run.

Ben Browder was the producer's and series creator's original choice for the role of Major John Sheppard. Joe Flanigan was hired for the role when Browder could not take the role due to filming Farscape: The Peacekeeper Wars (2004). Browder was later cast in the role of Lt. Col. Cameron Mitchell on Stargate SG-1 (1997).

David Hewlett based the character of Dr Rodney McKay on the nerds he used to work with in his IT days working for a voicemail company.

The character of Dr. Weir, played by Torri Higginson, was originated by Jessica Steen in the two-part story beginning with Stargate SG-1: Lost City: Part 1 (2004) on Stargate SG-1.

Rodney McKay was voted "One of TV's most annoying characters".

The on-set Stargate prop is composed primarily of vacuum-formed plastic panels on the front and rear faces with rubber caps on the circumference and cast resin chevrons.

Dr. McKay's full name is Meredith Rodney McKay.

The production crew actually have two Puddle Jumpers. The first is closed, and is used on location, and the second is an open Jumper that stays on set. The open jumper is used to film interior shots.

The load bearing vests worn by the "Stargate: Atlantis" team are Blackhawk Omega tactical vests.

Star Trek: Deep Space Nine (1993) is considered a strong influence behind the television series.

Joe Flanigan, David Hewlett, Rachel Luttrell, Paul McGillion, Amanda Tapping, David Nykl, Chuck Campbell and Gary Jones are the only actors to appear in all five seasons. Of these, only Nykl, Campbell and Jones were never regular cast members on the series.

The shooting set of the Stargate Atlantis base, specifically the balconies where the humans from Earth celebrated their first victory as well as several times depicting the outdoor dining area is the exact same location as the Colson Industries' main office building from Stargate SG-1: Covenant (2004).

Only three out of the ten regular actors from all seasons are American: Joe Flanigan and Robert Picardo, who also play American characters, and Jason Momoa, who plays an alien. David Hewlett, who was born in the UK, is the only regular who plays a Canadian character; The other six regular actors are Canadian: Torri Higginson, Rainbow Francks, Amanda Tapping and Jewel Staite, who play American characters; Rachel Luttrell, who plays an alien; and Paul McGillion, who plays a Scot (McGillion was actually born in Scotland).

Stargate's ring have 39 glyphs or chevrons. In this TV series as in Stargate SG-1 (1997) and Stargate Universe (2009) is explained that the number of glyphs in a stargate depends of the galaxy where this stargate belongs.

Dr. Leonard "Bones" McCoy, the epic character played by DeForest Kelley in Star Trek (1966), is considered a strong influence behind Rodney McKay. This is even acknowledged in-universe.

Jason Momoa would later go on to succeed Arnold Schwarzenegger as Conan the Cimmerian in Conan the Barbarian (2011) reboot of Conan the Barbarian (1982). Jewel Staite's Firefly (2002) /Serenity (2005) co-star Summer Glau played Cameron Phillips in the Terminator: The Sarah Connor Chronicles (2008), based on the films starring Arnold Schwarzenegger. Lena Headey, who played Sarah Connor in that series, would star opposite Jason Momoa in Game of Thrones (2011). Emilia Clarke, who stars in "Game of Throne" would go on to play Sarah Connor in Terminator Genisys (2015).

The machine is a system to open a wormhole. A wormhole is a hypothetical way of space travel called an Einstein-Rosen Bridge, named after scientists Nathan Rosen and Albert Einstein. According to them, the wormhole should capable to unite two distant points in the universe, altering Space-Time Laws to cross from a point to another in a so brief period of time. The name wormhole was given after a comparative between the universe and an apple, with a worm moving inside. The same concept was used in Contact (1997) as well as Stargate (1994) and their TV series Stargate SG-1 (1997) and Stargate Universe (2009).

Amanda Tapping, Robert Picardo, Jewel Staite, Joe Flanigan, Christopher Judge, David Hewlett, Jason Momoa, and Paul McGillion have attended the Armageddon Expo in New Zealand.

Although David Nykl and Paul McGillion were born in the Czech Republic (then Czechoslovakia) and Scotland respectively, both moved to Canada when very young and speak normally with a Canadian accent. The accent used for their characters comes from their parents.

Two of the main cast went on to be main characters in superhero series based on DC comics: David Nykl (Dr. Radek Zelenka) went on to play recurring and sometimes regular character Anatoly Knyaezev on Arrow and Jason Momoa (Ronon Dex) went on to play Arthur Curry/Aquaman in the DCEU. Paul McGillion (Dr. Carson Beckett) also went on to play minor recurring character Earl Cox on The Flash (which exists in the same on-screen universe as Arrow).

When on base, the uniform jackets have different colors on the chest: red for Elizabeth (command), black for military, blue for scientists, yellow for medical, green for operations.

The titular nemeses from Screamers (1995) are considered to be a possible influence behind the Replicators.

When first explaining the situation to Dr. Weir, McKay says "nothing, we'll call you" then touches his ear as if to end the transmission but he's clearly not wearing an ear piece.

In season1, it is stated that approximately 60 Wraith hive ships exist in the Pegasus Galaxy. Over the course of the series, and including a crossover episode with Stargate SG-1 (1997), whether shown on screen or stated by a character, only about 26 hive ships had been destroyed by series' end.

Richard Dean Anderson (Jack O'Neill) and Michael Shanks (Daniel Jackson) are the only two actors to appear in the pilots of both Stargate SG-1 (1997) and "Stargate: Atlantis". Amanda Tapping (Samantha Carter) and Gary Jones (Walter Harriman) are the only actors to appear in the final episodes of both series, as well as the only two actors to appear in the pilot of "Stargate SG-1" and the finale of "Stargate: Atlantis".

Joe Flanigan, David Hewlett, Rachel Luttrell, Paul McGillion and Amanda Tapping are the only regular actors who appeared in all five seasons (although Paul was a regular only for two seasons and Amanda just during Season 4). Torri Higginson, Jason Momoa and Jewel Staite appear in four seasons (although Jewel was a regular only during Season 5 and she played a different role in Season 2). Robert Picardo and Rainbow Francks appear in two seasons (they were only regulars in one season).

A stargate is a ring composed of a fictional superconductive mineral called "naqahdah", marked with 39 glyphs that operates using a combination of 7 glyphs or chrevrons to establish a space route to travel from a point to another. Using mathematical combinatorics, it implies that a single stargate can locate 77,519,922,480 places throughout the galaxy, increased to 45,379,620 if in the combination one of some glyphs can be re-used. Using a 8 glyphs combination for an extragalactic travel, a stargate can locate 2,480,637,519,360 places throughout the universe, increased to 5,352,009,260,481 if one or more glyphs can be re-used.