spectator sport

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A sporting activity which has a relatively high ratio of watchers to direct participants.
• noun idiomatic Something, especially a process or activity, which is a popular object of observation; an activity which a person prefers to watch rather than to participate in.
• noun idiomatic An activity which consists of watching or observing.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sport that many people find entertaining to watch