President Donald Trump on Wednesday said Facebook Inc. was biased against him during the election, marking the second time he has sought to rebut the notion that possible manipulation of the social network could have played a role in his election win.

The heated rhetoric comes as public scrutiny of the role of technology companies played in the election is set to heat up. On Wednesday, the Senate Intelligence Committee invited Facebook Inc., Alphabet Inc.’s Google and Twitter Inc. to testify on Nov. 1 about Russian interference...