Though in these posts I've tried to cover every character, there are some that just don't appear enough to have their own separate posts. So here I cover all of them I can think of (if there are more, I'm sorry for leaving them out), even though they've probably been mentioned in posts before.
磯貝 (Isogai) is an elderly lady who is the Furukawas' neighbor. She likes to comment on how Akio and Sanae add liveliness to the neighborhood (especially with their frequent episodes involving Sanae's bread). When Tomoya is going to the grocery store for the first time after remeeting Ushio, she reminds him of how important it is that he and Ushio see each other, since they are family, after all. Isogai also happens to have a name perfect for fake identities: both Fuko (when she's staying at the Furukawas' home) and Sanae (when she's Sunohara's fake girlfriend) adopt her last name to facilitate their deceit.
ボタン (Botan) is the pet boar of the Fujibayashis. Her characteristic sound is "Puhi puhi!" She has many skills, supposedly; the one that is shown is her ability to act like a stuffed animal (which Tomoya must then carry around with him all day). Kyou is particularly protective of her (especially from Sunohara, when he talks of eating her). She stays with Kyou well into her adult life, and she haunts Kyou's kindergarten playground as an adult (a giant, scary adult).
三井 (Mitsui) is a high school senior. Fuko met her on her first (and only) day of high school, and Mitsui vaguely remembers her. She is so studious and concerned about her upcoming senior exams that she coldly rejects Fuko's proffer of a starfish. Thankfully, she still shows up to Kouko's wedding, though.
"The bad man" is a former coworker with Kotomi's parents. On the day of their death, he (somewhat bluntly) informs Kotomi of the tragedy and asks to look in her father's study for a copy of the lost manuscript. He and Tomoya put out the fire Kotomi starts that day. Later on, he keeps trying to get in contact with Kotomi, who sees him as "the bad man" and reacts aggressively whenever he comes near. Eventually (thanks to Tomoya and Nagisa's help), he is able to talk to her, and he gives her her parents' suitcase containing the stuffed bear and their last letter to her. He is also Kotomi's godfather (I believe).
仁科りえ (Nishina Rie) and 杉坂 (Sugisaka) are members of the choir club, along with a minor third member, Harada. Rie (the blue-haired one) is the leader; her violin playing attracts Kotomi, and eventually Kotomi is given her violin (though that was probably not a wise decision...). Sugisaka (the red-haired one) is the fiery, jealous one; when the drama club wants Koumura as an adviser, she takes action, leaving threatening letters for Nagisa and trying to win her over with a sad story (which Sunohara fiercely rejects). Though she gives in after the basketball game, she's still the more angry of the two. The club shows up at Nagisa's graduation, and the two seem to be good friends, as they are shown to be roommates (it appears) during the final montage.
坂上鷹文 (Sakagami Takafumi) is Tomoyo's younger brother. He grows distant from her due to her being a gang leader. When their parents are considering divorce, Takafumi takes drastic action: he promises to jump off a bridge if they don't reconsider, and he keeps his promise. This leads to a long hospitalization for him, one which brings the family together and ends the thought of divorce. While he was recovering, the whole family would take walks along the road lined with cherry trees (thus providing Tomoyo's urge to save them). His desperate action also knocked some sense into Tomoyo's head, giving her the push to be a true sister to him and renounce her gang ways.
五十嵐 (Igarashi) was Misae's crush back during her high school days. She first met Shima when he interrupted a conversation between the two of them. He recognizes that Misae has a crush on him, but he already has a girlfriend. He gets Shima to break the news to her for him (although seeing him and his girlfriend walk by is what really gives her the news). Because of this moment, Shima and Misae started to grow closer.
勇 (Yuu) is a young boy whose sister is in Yukine's brother's gang. He tries to grapple Yukine and force her to tell him where his sister is. Though she easily defuses the situation, she is kind and takes him to the bar where the gang hangs out, thus helping him find his sister. He tells the gang that Sunohara is Yukine's brother, thus causing a bit of an uproar at the deception. He helps instigate Tomoya, Nagisa, and Sunohara's involvement with Yukine's gang.
宮沢和人 (Miyazawa Kazuto) was Yukine's older brother. He was the leader of the gang that Yuu's sister is in and that Yukine hangs out with a lot. Because of him, Yukine became involved with the gangs (although not really in a negative way, like what happened with Tomoyo). Due to his blond hair, Sunohara sort of spreads a rumor that he's Kazuto, which leads to his getting attacked one night (thankfully Tomoyo saves the day). When his deception is revealed at Kazuto's gang, it's learned that Kazuto is really in the hospital for getting in a car accident and saving a friend. The other gang wants to fight, though, so a duel is created between their leader and "Kazuto" (Sunohara). After Sunohara is knocked out by Sanae's bread, Tomoya takes over the fight, until Yukine steps in, posing as Kazuto. Finally, after this, the truth is revealed: Kazuto is actually dead, and his deepest wish was that the fighting would stop, which ends up happening thanks to the above events. And when his wish is fulfilled, Tomoya sees a light fly up into the air...
The manager of the Hikarizaka Electric Company (at least one branch of it) is Yuusuke's and later Tomoya's boss. He's a hard working man who cares about his employees and tries to be as kind as possible to them. Sometimes (especially after Nagisa passes away), he suspects Tomoya works far too much, and he tries to get him to relax more. He also recommends Tomoya for a job at another part of the company in a different city. Tomoya deeply considers accepting it, until his manager informs him that he was turned down from the job due to his father's arrest on drug charges (I think that's what they were, at least). Tomoya's anger because of this leads to his confronting his father and also proposing to Nagisa.
Yagi is Nagisa's midwife, recommended by Sanae. She helps Nagisa prepare for home birth, and she's able to make it to the Okazaki residence (after a long delay) on the night Nagisa goes into labor. Though she's able to save the baby, she's unable to save Nagisa's life (at least the first time). She also may have been the one to suggest Nagisa abort Ushio when her severe health risk is brought to light (I only remember that someone suggested this; I can't remember who just at the moment).
I believe that's the majority of the minor characters (or really minor minor, since I call anyone except Nagisa, Tomoya, and Ushio minor characters, basically). Hopefully having these extra profiles helps you realize even more how great Clannad is and how much its characters form a mosaic. If I forgot any characters, let me know, and I can add them in.
Thanks for reading. God Bless, and peace.
Nota Bene: All images are screenshots taken by me from the subtitle-only DVDs. Please support Clannad by buying the DVDs. And don't forget to look at the amazing CLANNAD/クラナド (Kuranado) fanpage on Facebook.