If your nationality is one of the list, you don't need to apply for a Visa for entering in Uganda:

1. Antigua and Barbuda
2. Bahamas
3. Barbados
4. Belize
5. Botswana
6. Burundi
7. Comoros
8. Cyprus
9. Democratic Republic of Congo
10. Eritrea
11. Fiji
12. Gambia
13. Ghana
14. Grenada
15. Ireland
16. Jamaica
17. Kenya
18. Lesotho
19. Madagascar
20. Malawi
21. Malaysia
22. Malta
23. Mauritius
24. Rwanda
25. Seychelles
26. Sierra Leone
27. Singapore
28. Solomon Islands
29. South Sudan
30. St. Vincent & The Grenadines
31. Swaziland
32. Tonga
33. Trinidad and Tobago
34. United Republic of Tanzania 
35. Vanuatu
36. Zambia
37. Zimbabwe