Mezinárodní všeodborový svaz '(International All-Trade Union League', abbreviated MVS, German: Internationalen Allgewerkschaftlichen Verband, abbreviated IAV) was a national trade union centre in Czechoslovakia.
MVS was founded in October 1922, after communists had been expelled from the Odborové sdružení českoslovanské (Czechoslav Trade Union Association, OSČ).
At the time, MVS was the third largest trade union centre in Czechoslovakia.
This made the work of building communist, red, fractions inside OSČ unions more difficult for KSČ.
In 1930, after a brief existence as an independent trade union centre, MVS merged back into OSČ.