The 41-year-old, who presents Extreme Makeover: Home Edition, was stopped by police in Los Angeles at 12.35am on Saturday (05May07) morning.
He was released two hours later after posting $5,000 (GBP2,500) bail.
In a statement, Pennington says, "I made an error in judgment. We all make mistakes, however this is about accountability. Under no circumstances should anyone consume alcohol while driving.
"I could have jeopardised the lives of others and I am grateful there was no accident or harm done to anyone. This was my wake-up call.
"I also want to apologise to my fans, ABC Television and my design team for my lapse in judgment and the embarrassment I have caused."
Source: WENN