Below, in chronological order, is a representation of those who fasted in the Bible, but it is not a complete or exhaustive list.

Moses

(Exodus 34:28), in a 40-day radical fast (no food or water), sustained by the Lord as he received the 10 commandments

The Israelites

(Judges 20:26-27), in a corporate fast, to seek the Lord's guidance

(Nehemiah 9:1), in a corporate fast, confessing their sins and worshiping the Lord

(1 Samuel 7:6), led by Samuel in a corporate and intercessory fast, repenting for their sins

King David

(2 Samuel 12:16), in intercession for his ill son

(Psalm 35:13) in mourning and intercession for the illness of others

(Psalm 69:10) in humble repentance, asking God for personal mercy and restoration

Elijah

(1 Kings 19:8) in a 40-day radical fast, prompted and sustained by the Lord

Ezra

(Ezra 8:21-23), in humble petition before the Lord

Esther

(Esther 4:16), in a three-day fast, accompanied by fasting intercessors, as she sought the Lord's favor in interceding for the Jews

The Ninevites and the King of Nineveh

(Jonah 3:5-10), in a corporate fast, earnestly repenting of their evil ways

Jesus

(Matthew 4:2, Luke 4:2), in preparation for His earthly ministry

New Testament Leaders and Prophets

(Acts 13:1-3), in worship of the Lord before He instructed them to set apart Barnabus and Saul for His designated missionary appointment

Paul and Barnabus

(Acts 14:23), in committing the appointed church elders to the Lord

The Great Commandment, as Jesus replied to the Pharisees in Matthew 22:37-38 is to "Love the Lord your God with all your heart and with all your soul and with all your mind. This is the first and greatest commandment. And the second is like it: Love your neighbor as yourself."

Fasting, as outlined in Isaiah 58, accomplishes both the first and second greatest commandments and also highlights the "true" fast (indicated by actions representative of Christ's character) as opposed to the "legalistic" fast (indicated by actions representative of arrogant, sinful, and unrepentant human hearts).