| Merthyr Tudful to Yonkers (New York) | 3,307.52 mi (5,322.93 km) |
| Merthyr Tudful to Yorba Linda (California) | 5,317.72 mi (8,558.05 km) |
| Merthyr Tudful to York (Pennsylvania) | 3,467.38 mi (5,580.20 km) |
| Merthyr Tudful to Yorktown (Indiana) | 3,810.64 mi (6,132.63 km) |
| Merthyr Tudful to Yorkville (Illinois) | 3,857.46 mi (6,207.98 km) |
| Merthyr Tudful to Youngstown (Ohio) | 3,575.93 mi (5,754.91 km) |
| Merthyr Tudful to Youngsville (Louisiana) | 4,560.42 mi (7,339.29 km) |
| Merthyr Tudful to Ypsilanti (Michigan) | 3,643.19 mi (5,863.14 km) |
| Merthyr Tudful to Yuba City (California) | 5,143.45 mi (8,277.59 km) |
| Merthyr Tudful to Yucaipa (California) | 5,285.33 mi (8,505.92 km) |
| Merthyr Tudful to Yucca Valley (California) | 5,259.50 mi (8,464.35 km) |
| Merthyr Tudful to Yukon (Oklahoma) | 4,512.62 mi (7,262.37 km) |
| Merthyr Tudful to Yulee (Florida) | 4,103.53 mi (6,603.99 km) |
| Merthyr Tudful to Yuma (Arizona) | 5,280.67 mi (8,498.41 km) |
| Merthyr Tudful to Zachary (Louisiana) | 4,497.87 mi (7,238.62 km) |
