I read from some sources that the dream of every sportsman, the Olympic Gold Medal, is not 100% pure gold. (Olympic Gold medals are required to be made from at least 92.5% silver, and must contain a minimum of 6 grams of gold).
Yes, some sports competitions still give out solid gold awards to the winners.
According to Wikipedia, the Kentucky Derby awards the only solid gold trophy in sports.
Professional sports championship rings (such as Super Bowl rings, World Series rings, and NBA championship rings), are usually solid gold.
Championship belts are usually gold plated. However, there are occasionally solid gold championship belts made for special events, such as the 2013 WBC Mayweather vs. Alvarez belt and the 2015 WBC Mayweather vs Pacquiao belt (source).
To be clear, although these examples are solid gold, they are not always pure 24K gold; they may be a lesser purity number.