If a Sacrifice fly is caught in foul territory is it counted as an at bat?

A batter is not charged with an at bat when he is credited with a sacrifice fly or sacrifice bunt. The main issue is the umpire's judgement: did the batter purposely sacrifice himself in order to move up the runner(s) with less than 2 outs? If so-- and if the runners did move up or score successfully-- he shall not be charged with an at bat.

Baseball's accounting therefore does not penalize a batter if he sacrificed himself for the team's benefit. (An at bat with a fly or bunt out would lower the batter's batting average.)

Source: Official Baseball Rules 10.08