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. Mozambique
25. Rwanda
26. Seychelles
27. Sierra Leone
28. Singapore
29. Solomon Islands
30. South Sudan
31. St. Vincent & The Grenadines
32. Swaziland
33. Tonga
34. Trinidad and Tobago
35. United Republic of Tanzania 
36. Vanuatu
37. Zambia
38. Zimbabwe