AlphaGo versus Fan Hui was a five-game Go match between European champion Fan Hui, a 2-dan (out of 9 dan possible) professional, and AlphaGo, a computer Go program developed by DeepMind, held at DeepMind's headquarters in London in October 2015. AlphaGo won all five games. This was the first time a computer Go program had beaten a professional human player on a full-sized board without handicap. This match was not disclosed to the public until 27 January 2016 to coincide with the publication of a paper in the journal Nature describing the algorithms AlphaGo used.

Fan described the program as "very strong and stable, it seems like a wall. ... I know AlphaGo is a computer, but if no one told me, maybe I would think the player was a little strange, but a very strong player, a real person."

In this match, DeepMind used AlphaGo's distributed version with 1,202 CPUs and 176 GPUs with Elo rating 3,144. For each game there was a one-hour set time limit for each player followed by three 30-second byo-yomi overtime periods.

During this match, AlphaGo and Fan Hui also played another five informal games with shorter time control (each player having just three 30-second byo-yomi) and AlphaGo defeated Fan by three to two.

Fan Hui (black) v. AlphaGo (white), 5 October 2015, AlphaGo won by 2.5 points.

AlphaGo (black) v. Fan Hui (white), 6 October 2015, AlphaGo won by resignation. Although the white stones at the lower-left corner could have been captured if black 135 had been placed at "a", AlphaGo's choice might be safer to win.

Fan Hui (black) v. AlphaGo (white), 7 October 2015, AlphaGo won by resignation.

AlphaGo (black) v. Fan Hui (white), 8 October 2015, AlphaGo won by resignation.