Williams Omnibus Bus Lines was the first mass transportation system in the old City of Toronto, Canada with four six-passenger buses. Established in 1849 by local cabinetmaker Burt Williams, it consisted of horse-drawn stagecoaches operating from the St. Lawrence Market to the Red Lion Hotel in Yorkville. The bus line was a great success, and four larger vehicles were added in 1850. After a few years, even more buses were in use, and were operating every few minutes. In 1861, the city gave a 30-year franchise for to Toronto Street Railways who built a horse car line, and the gauge of the buses was modified so as to fit between the tracks. The bus system lasted only until 1862, when it was bought out by the TSR. The omnibuses were manufactured by Williams' own cabinet-making store on Yonge Street, H. Burt Williams.
Prior to Williams' operations, there were a variety of stagecoach operators in the city:
| Builder | Description | Fleet size | Year acquired | Year retired | Notes |
| H. Burt Williams cabinet store, Toronto | small omnibus (6 passenger stage coach) | 4 | 1849 | 1862 | horse drawn stagecoach |
| H. Burt Williams cabinet store, Toronto | large omnibus | 4 | 1850 | 1862 | horse drawn stagecoach |
The companies and agencies that succeeded Williams:
| Preceded by None |
Public Transit in Toronto 1849-1861 |
Succeeded by Toronto Street Railways |