Female Transformer
Despite being robotic lifeforms with generally non-sexual methods of reproduction, the Transformer species has almost always been shown to include both male and female gender analogues, at least mentally if not physically. Female Transformers are usually portrayed as comparatively rare, but are considered an official part of the Transformers franchise in every continuity.
Appearence
The appearence of Female Transformers in most continuities would seem to suggest a level of "sexual" dimorphism is present in at least the more humanoid members of the Transformers species (the term sexual is used in a gender-based, rather than physical sense, see the reproduction link above for that whole kettle of robo-fish). In almost all cases female Transformers are portrayed as comparatively more gracile of form, and more rounded and curved in general, than their male counterparts. Often they have a more than passing resemblance to an attractive human female made of metal and wearing armor and kibble.
There are exceptions to this rule, and bulky, less overtly human-female-like characters have become more common, particularly among those who have toys. These are especially common in the Unicron Trilogy series and in latter expansions of the Generation 1 series out of Japan, when the characters are often assigned to pre-existing "male"-designed toys.
Romance
Despite their robotic nature and likely non-sexual means of reproduction (again see the link above), romance between male and female Transformers is a well-established factor in pretty much every continuity in which both appear (which is pretty much every continuity).
In the Generation 1 animated continuity it is concievable that these tendencies to form romantic bonds might steam from Quintesson mental programming that emulates the organic beings the Transformers were originally built to serve. Though this is only speculation.
Regardless of the whys and wherefores many romantic male-female Transformer parrings have appeared over the years, including:
- Beta - Alpha Trion
- Elita One (Aerial) - Optimus Prime (Orion Pax)
- Firestar - Inferno
- Chromia - Ironhide
- Moonracer - Powerglide
- Arcee - Hot Rod
- Arcee - Springer
- Arcee (she gets around)- Chromedome
- Esmeryl - Deathsaurus
- Clipper - Holi
- Rahge - Stampy
- Airazor - Tigatron
- Blackarachnia - Silverbolt
- Strika - Obsidian
- Botanica - Rattrap
Fiction
Generation 1 animated series
Only female Autobots are ever seen in the show. Given the appearence of Beta back in the slave days under Quintesson rule it seems clear they were produced alongside the male Autobots as part of the Quintesson's domestic product line, likely for those races that prefered female-style servants.

It seems from all evidence (though it is not confirmed) that the millitary hardware line may not have possessed a counterpart to this, thus no female Decepticons are ever seen. (The Japanese fiction however does include such Decepticons, see the Victory section bellow).
Generation 1 Marvel Comic
No female Transformers are ever seen or refered to in the US stories. The UK stories specifically establish that the Transformers as having no gender naturally, and there, Arcee is created as the sole female Transformer in an attempt to placate human feminists (See her picture above for a hint of how well that went over).
(This continuity has, historically, been surprisingly alone in declaring Transformers to be naturally gender free.)
Transformers: Victory manga
Decepticon females make their rare (only?) appearence in official fiction as Esmeryl (Deathsaurus' wife) and Lyzack (Leozack's sister) both show up to show the Autobots just what it is Deathsaurus and his crew have been fighting for all this time: their poor female counterparts and countless children back home. This spares the Decepticons' lives in the final battle between the two forces.
Beast Wars
Blacharachnia and Airrazor both engage in romances with male Maximals, the one blatantly and the other more subtle.
Over the course of the show Rattrap makes numerous innuendoes, especially involving Silverbolt and Blackarchnia's relationship, that suggest that, at least by that era, there *may* have been something sex-like between TFs. (Though likely recreational rather than reproductive from what we know.)
Beast Wars II
Beast Machines
Beast Machines' Technorganic reformating raises even further questions about what it means to be a "female transformer". It is possible that the Technorganic female Transformers, being merged organic and technological life to a cellular level, might actually be physically female and capable of bearing young, but that remains speculation.
Dreamwave comic continuity
According to DK's Transformers: The Ultimate Guide, "Transformers are inherently non-gender specific, and only some quirk of their timelost origins can account for their (female Transformers) difference in appearance and attitude." Dreamwave was in the process of introducing more female Transformers and explicating their links to the Quintessons in this continuity when it went out of buisness.
Unicron Trilogy
The existance of female Transformers throughout the Unicron Trilogy is portrayed as somewhat uncommon (it is a fiction aimed at young boys, after all), but hardly remarkable. They just exist. There are examples of romantic interest between males and females in both Armada (Redline and Falcia in the Linkage comics), and Cybertron stories (most obviously Thunderblast's intense crush on Megatron). There are female Transformers in positions of very high power as well: in the Energon cartoon, Arcee is the leader of the entire Omnicon race, while in Cybertron, Override is the leader of the planet Velocitron.
IDW Comic continuity
Simon Furman has stated that he will not use female Transformers in the IDW continuity untill or unless he comes up with a reason/way for them to exist that makes logical sense to him. He did not rule out doing so however, as he said he had found a similar justification for the Pretenders, which lead to the Stormbringer miniseries.


