Step 1: Recall what the Henley Passport Index measures.
It ranks countries by how many destinations their passport holders can enter without needing a prior visa.
Step 2: Eliminate the countries that are not known for topping this index.
England, Sri Lanka and India all have decent passport rankings but none of them has held the top spot for three straight years.
Step 3: Recall the actual topper.
Singapore has consistently held the number one position, and 2026 marked its third year in a row at the top.
\[ \boxed{\text{Singapore}} \]