Fischer had said he would not speak to such a potential coalition since he is running for the non-partisan presidency, but in public comments he said he found the idea distasteful, Austrian newspaper Die Presse reports.
Fischer said he could not support any connection with Haider, who has spoken favorably of some Nazi policies.
The possibility of a coalition between Austrian Social Democrats and Haider's Freedom Party arose when the Freedom party won 42 percent of votes in the Austrian state of Carinthia in March 7 elections. Social Democrats finished second, with 38 percent of the vote.
Haider's influence in Austria seemed to have waned, but his party's strong results in Carinthia put him in position to once again attempt to become a major player in Austrian politics on the national level.