Label

Element

Value

Risk/Return:

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Registrant Name

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Fidelity Colchester Street Trust

Prospectus Date

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May 30, 2015

IV | Treasury Only Portfolio

Risk/Return:

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Supplement [Text Block]

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Supplement to the
Fidelity^® Institutional Money Market Funds
Class IV
May 30, 2015
Prospectus

The following information supplements information for Treasury Only Portfolio and for Treasury Portfolio found in the "Fund Summary" section under the heading "Principal Investment Risks" on pages 8 and 12.

The fund will not impose a fee upon the sale of your shares, nor temporarily suspend your ability to sell shares if the fund's weekly liquid assets fall below 30% of its total assets because of market conditions or other factors.