Steam locomotives with names beginning with U that have operated in North America:
| Name | Railroad, # | Builder, s/n | Build date | Whyte type | Notes |
|---|---|---|---|---|---|
| U. S. Grant | CP 81 | Cooke | 2/1868 | 4-4-0 | Rn 1891 #1206; scr 10/1899 at Sacramento. |
| U. S. Mountain | D&RG 76 | Baldwin 5184 | 7/1880 | 2-8-0 | Sold to Rio Grande Western as #76; sold to Rio Grande Southern as #31; sold 2/1900 to Morenci Southern Railway as #3. |
| Ukiah | SF&NP 11 | Union 30 | 1882 | 4-4-0 | Scrapped 8/18/1907. |
| Ulster | NYOW 9 | Rhode 125 | 9/1869 | 4-4-0 | Sold 10/22/1887 to New York Locomotive Works; sold 4/1888 to Centralia & Chester. |
| Uman | FCUY 32 | Baldwin 7144 | 2/1884 | 4-4-0 | Ex-FCM&C #2; scr 1955. |
| Umpqua | CP 124 | Globe | 1865 | 4-4-0 | Rn 1891 #1212; scr 9/10/1906 at Sacramento. |
| Unadilla | NYOW 60 | Baldwin 3082 | 1/1873 | 2-6-0 | Sold 1/10/1907 to Southern Iron & Equipment Company as #568; sold 3/1/1907 to Florala Sawmill Company of Paxton, Florida, as #3; traded 3/13/1913 back to SI&E; sold to Louisiana Sawmill Company of Alexandria, Louisiana, as #50. |
| Uncas | NY&H | Rogers 364 | 1/1853 | 4-4-0 | |
| Uncle Dick | NM&SP 204 | Baldwin 4500 | 2-8-0T | Sold to ATSF as #204. | |
| Uncle Sam | ASC | Baldwin | 0-6-2 | Sold 1901 to Honolulu Sugar Company; rb 1901 as a tank engine. | |
| Uncle Sam | NJR&T 11 | Rogers 11 | 3/1839 | 4-2-0 | First locomotive built in the US with an eight-wheel tender. |
| Uncle Tom | BCIF | 4-2-2 | Inside connected. | ||
| Uncle Tom | Bo&P | Griggs | 1851 | 2-2-2 | Ex-Dedham; sold to Fitchburg & Worcester Railroad; rb as 4-2-2; in use on the New York & Flushing Railroad into the 1870s. |
| Uncompahgre | D&RG 75 | Baldwin 5166 | 1880 | 2-8-0 | |
| Unicorn | CP 46 | M & Aldus | 9/1867 | 4-6-0 | Rn 1891 #1259; rb 6/5/1872 as a 4-4-0; scr 12/19/1904 at Sacramento. |
| Union | P&HR | Rogers 283 | 10/1851 | 4-4-0 | |
| Union | SF&SJ 8 | Union 6 | 1865 | 0-4-0 | Rn 1891 #1002; sold 7/28/1892 to Santa Cruz & Watsonville. |
| Union | USM | Baldwin 1061 | 6/1862 | 4-4-0 | Sold to B&O after 1865. |
| Unionville | NYOW 57 | Baldwin 3009 | 11/1872 | 2-6-0 | Scrapped 10/1895. |
| United States | LV 310 | Baldwin | 1876 | 2-8-0 | |
| United States | P&R | Baldwin | 1848 | 0-6-0 | |
| Ures (1st) | FCDS 8 | Rhode 940 | 5/1881 | 4-4-0 | Rn 8/17/1907 #63; off roster by 8/1/1911; became California Southern #8. |
| Ures (2nd) | FCDS 8 | Manch 1009 | 11/1881 | 4-4-0 | Became California Southern #9. |
| Ures (3rd) | FCDS 8 | Rhode 1083 | 12/1881 | 4-4-0 | |
| Utah | CP 9 | Cooke | 7/1865 | 2-6-0 | Rb 12/9/1871 as a 4-4-0; rb 1891; scr 6/12/1901 at Sacramento. |
| Utah | U&N 4 | Grant | 11/1871 | 4-6-0 | Rn #285; scrapped c. 1886. |
| Ute | D&RG 6 | Baldwin 2613 | 1871 | 2-4-0 | |
| Ute | KPDP 25 | Baldwin 1614 | 1867 | 4-4-0 | |
| Utica | M&SC | Rogers 256 | 4/1851 | 4-4-0 | |
| Utica | NYOW 68 | Rhode 430 | 9/1872 | 2-6-0 | Ex-#78 Courtland. |
| Utowana | Adir 4 | Schen 1922 | 1884 | 4-4-0 | Became D&H #411 |