William Henry "Big Bill" Caley (July 1873 – January 15, 1918) was an American football player, lawyer, and mine operator.

After graduating from Michigan, he returned to Colorado where he practiced law and operated grocery and mining businesses.

His father operated a hotel and engaged in the mining, cattle, and butcher businesses at Alma, Colorado.

As team captain, he led a group that recruited Fred Folsom to the University of Colorado as its football coach in 1895.

[9] In 1904, a writer in the Denver Times wrote that Caley was "probably the best football player ever turned out of the University of Colorado.

[10] While watching the team practice one night, Michigan's football coach William Ward spotted Caley and asked him to put on a uniform and play.

The Michigan Alumnus praised Caley for his efforts against Chicago: He took up the duties of his new [fullback] position in perfect style, and soon showed that he was fairly entitled to be called the best all-round football player on the 'Varsity this year.

[17]The University of Michigan yearbook for 1899 included a poem titled "Mighty Bill" dedicated to Caley's efforts against Chicago.

In part, the poem states: King Somus called around last night And quite a time we had, – Talking 'bout the game in which Bill Caley knocked 'em sad – ... Chicago thought they had a cinch In fact I think they did; Till Billiam took his good right foot And kicked the little lid[18] At the end of the 1898 season Caspar Whitney (the originator of the practice of naming All-American teams) and the Chicago Daily Tribune both selected Caley as a first-team member of their All-Western teams.

[19][20] The Chicago Daily Tribune wrote: "Caley is another excellent guard, although Michigan used him at full back.

[21] He finished in second place in the discus throw at the Western Collegiate Athletic Meet held at Marshall Field in Chicago on June 4, 1898.

At the time of the 1900 United States census, he was living in the Cripple Creek District at Victor, Colorado, where he was employed as an attorney.

He died in January 1918 at the Cash Entry mine in Los Cerillos, Santa Fe County, New Mexico, when he became caught in an engine belt and was "torn to pieces.