Farmers in Ethiopia cultivate onion as a cash crop after the main crop harvest seasons. However, transplanting 8 to 10 weeks-old seedlings to the main field is a labour-intensive operation. Now a day, transplanting is carried out through mechanization scheme. In this research, design and fabricate of onion seedling transplanting machine was designed and fabricated. Moreover, this machine can also be used for pepper and rice transplanting as required. Manufactured transplanting machine test shows promising results. However, further modification requires adapting for different seedling transplanting. In 20th century transplanter was invented to plant the seedling into the land which reduced the human efforts and consumed less time. The distance between seedlings was designed 20cm. This transplanting machine is an agricultural machine used for transplanting seedlings to the field. In this thesis work design a mechanism for transplanting onion seedlings, preparing 2D and 3D drawing using solid work software, assemble the manufactured components and test the performance of the machine has been included.