Rupp took part in the Great Edinburgh Cross Country in 2011 and finished second behind Mo Farah, helping the American team to second place. He then took part in the New York City Half Marathon, his debut at that distance and finished third in a time of 1:00:30, making him the third-fastest American at the distance. At the 2011 USA Outdoor Track and Field Championships he once again retained his national 10,000 m title, running the last 800 meters in a quick 1:52.59, and came back the next day to finish third in the 5000 m. Later in July, he improved his 5000 m personal best to 13:06.86 at the Diamond League meeting in Birmingham, outsprinting the reigning world cross country champion Imane Merga for second behind winner Mo Farah.