Φίλιπποι

Acts 16:12 Φιλίππους, Philippi,

From there we went to the Roman colony of Philippi, the leading city of that district of Macedonia. And we stayed there several days.

Acts 20:6 Φιλίππων Philippi

And after the Feast of Unleavened Bread, we sailed from Philippi, and five days later we rejoined them in Troas, where we stayed seven days.

Philippians 1:1 Φιλίπποις Philippi

Paul and Timothy, servants of Christ Jesus, To all the saints in Christ Jesus at Philippi, together with the overseers and deacons:

Here: The city's name is grammatically plural. It was named after Philip II of Macedon and by Paul's day it was a Roman military colony.

1 Thessalonians 2:2 Φιλίπποις, Philippi,

As you are aware, we had already endured suffering and shameful treatment in Philippi. But in the face of strong opposition, we were bold in our God to speak to you the gospel of God.

Here: The Roman colony in Macedonia about 150 km east of Thessalonica, on the Via Egnatia. It was Paul's previous stop and the scene of the beating and imprisonment.