The Düsseldorf Open was a women's clay court tennis tournament founded as a combined men's and women's tournament in 1905 called the Düsseldorf International or Internationale Düsseldorf.^[1] It remained a joint event until 1969 and was held annually at the Rochusclub Düsseldorfer Tennisclub in Düsseldorf, Germany until 1974.^[1]

In 1898 the Rochusclub Düsseldorfer Tennisclub was founded.^[2] In 1905 the club staged the first Internationale Düsseldorf tournament.^[1] In 1906 a womens event was added to the schedule. In 1929 the Rochusclub moved to a new location where it remains today.^[3] It was held annually in Düsseldorf, Germany until 1974.^[1] The combined event was part of the Deutscher Lawn Tennis Bund (f.1902) circuit from inception until 1913.^[1] In 1914 it became part of the new ILTF Circuit until 1969.^[1] In 1970 the men's event was re branded as the Düsseldorf Grand Prix and became part of the Grand Prix tennis circuit.^[1] The women's event remained a part of the ILTF Circuit under the original name Dusseldorf International. In 1973 the women's event was branded as the Düsseldorf Open and was part of the 1973 WTA Tour for one edition only, before it returned as an event on the ILTF Independent Tour. The women's event ended in 1974 and the men's tournament was discontinued in 1977.^[1]

The Düsseldorf Open was a women's professional tennis tournament held for one year, in 1973, in Düsseldorf, West Germany. Its one-year on the WTA Tour saw a home player, Helga Masthoff, triumphing in the women's singles, whilst she and Heide Orth reached a women's doubles final that was never played.

• Düsseldorf Grand Prix
• ATP Düsseldorf Open