The Manchu alphabet (Manchu: ᠮᠠᠨᠵᡠ ᡥᡝᡵᡤᡝᠨ, Möllendorff: manju hergen, Abkai: manju hergen) is the alphabet used to write the now critically endangered Manchu language. A similar script called Xibe script is used today by the Xibe people, whose language is considered either a dialect of Manchu or a closely related, mutually intelligible language. It is written vertically from top to bottom, with columns proceeding from left to right.

The Jurchens of a millennium ago became the ancestors of the Manchus when Nurhaci united the Jianzhou Jurchens (1593–1618) and his son subsequently renamed the consolidated tribes as the "Manchu". Throughout this period, the Jurchen language evolved into what we know as the Manchu language. The Jurchen script has no relation to the Manchu alphabet, as it was derived from the Khitan script, itself derived from Chinese characters. After the collapse of the Jin dynasty, the Jurchen script fell into disuse.

According to the Veritable Records [zh] (Manchu: ᠮᠠᠨᠵᡠ ᡳ ᠶᠠᡵᡤᡳᠶᠠᠨ ᡴᠣᠣᠯᡳ, Möllendorff: manju i yargiyan kooli; Chinese: 滿洲實錄; pinyin: Mǎnzhōu Shílù), in 1599 the Jurchen leader Nurhaci decided to convert the Mongolian alphabet to make it suitable for the Manchu people. He decried the fact that while illiterate Han Chinese and Mongolians could understand their respective languages when read aloud, that was not the case for the Manchus, whose documents were recorded by Mongolian scribes. Overriding the objections of two advisors named Erdeni and G'ag'ai, he is credited with adapting the Mongolian script to Manchu. The resulting script was known as tongki fuka akū hergen (Manchu: ᡨ᠋ᠣᠩᡴᡳ ᡶ᠋ᡠᡴᠠ ᠠᡴᡡ ᡥᡝᡵᡤᡝᠨ) — the "script without dots and circles".

In 1632, Dahai added diacritical marks to clear up a lot of the ambiguity present in the original Mongolian script; for instance, a leading k, g, and h are distinguished by the placement of no diacritical mark, a dot, and a circle, respectively. This revision created the standard script, known as tongki fuka sindaha hergen (Manchu: ᡨ᠋ᠣᠩᡴᡳ ᡶ᠋ᡠᡴᠠ ᠰᡳᠨ᠋ᡩ᠋ᠠᡥᠠ ᡥᡝᡵᡤᡝᠨ) — the "script with dots and circles". As a result, the Manchu alphabet contains little ambiguity. Recently discovered manuscripts from the 1620s make clear, however, that the addition of dots and circles to Manchu script began before their supposed introduction by Dahai.

Dahai also added the tulergi hergen ("foreign/outer letters"): ten graphemes to facilitate Manchu to be used to write Chinese, Sanskrit, and Tibetan loanwords. Previously, these non-Manchu sounds did not have corresponding letters in Manchu. Sounds that were transliterated included the aspirated sounds k' (Chinese pinyin: k, ᠺ), k (g, ᡬ), x (h, ᡭ); ts' (c, ᡮ); ts (ci, ᡮ᠊ᡟ); sy (si, ᠰ᠊ᡟ); dz (z, ᡯ); c'y (chi, ᡱᡟ); j'y (zhi, ᡷᡟ); and ž (r, ᡰ).

By the middle of the nineteenth century, there were three styles of writing Manchu in use: standard script (ginggulere hergen), semi-cursive script (gidara hergen), and cursive script (lasihire hergen). Semicursive script had less spacing between the letters, and cursive script had rounded tails.

The Manchu alphabet was also used to write Chinese. The way in which this was done is explained in Manchu: a Textbook for Reading Documents, which has a comparative table of romanizations of Chinese syllables written in Manchu letters, Hànyǔ Pīnyīn and Wade–Giles. Using the Manchu script to transliterate Chinese words is a source of loanwords for the Xibe language. Several Chinese-Manchu dictionaries contain Chinese characters transliterated with Manchu script. The Manchu versions of the Thousand Character Classic and Dream of the Red Chamber are actually the Manchu transcription of all the Chinese characters.

In the Imperial Liao-Jin-Yuan Three Histories National Language Explanation (欽定遼金元三史國語解 Qinding Liao Jin Yuan sanshi guoyujie) commissioned by the Qianlong Emperor, the Manchu alphabet is used to write Evenki (Solon) words. In the Pentaglot Dictionary, also commissioned by the Qianlong Emperor, the Manchu alphabet is used to transcribe Tibetan and Chagatai (related to Uyghur) words.