磷酸鉀

{{chembox
| Watchedfields = changed
| verifiedrevid = 442343633
| ImageFile = Tripotassium phosphate.png
| ImageSize = 150px
| ImageFile1 = Kaliumphosphat.png
| ImageSize1 = 200px
| ImageCaption1 = Unit cell of tripotassium phosphate.
| ImageAlt1 = Unit cell of the anhydrous tripotassium phosphate under standard conditions (low temperature modification).
| ImageFile2 = K3PO4_sample.jpg
| IUPACName = Potassium phosphate
| SystematicName = Potassium tetraoxidophosphate(3−)
| OtherNames = Potassium phosphate, tribasic
|Section1=
|Section2=
|Section3={{Chembox Structure
| Structure_ref =
| CrystalStruct = 正交P
| LattConst_a = 1.123772 nm
| LattConst_b = 0.810461 nm
| LattConst_c = 0.592271 nm
| LattConst_ref =

制备
磷酸钾可由磷酸铵（(NH4)3PO4）和氯化钾（KCl）的复分解反应制得，溶解度较小的一者将沉淀：
:(NH4)3PO4 + 3KCl -> K3PO4 + 3NH4Cl

氢氧化钾和磷酸或磷酸二氢钾的反应也用于制备磷酸钾：、催化剂等。
参考文献
参见

• 磷酸二氢钾（KH2PO4）
• 磷酸氢二钾（K2HPO4）
• 焦磷酸钾（K4P2O7）
• 磷酸钠（Na3PO4）