UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported)

April 23, 2012

TIBCO Software Inc.

(Exact name of registrant as specified in its charter)

3303 Hillview Avenue

Palo Alto, California 94304-1213

(Address of principal executive offices, including zip code)

(650) 846-1000

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 1.01. Entry into a Material Definitive Agreement.

On April 23, 2012, TIBCO Software Inc. (“TIBCO”) entered into an indenture (the “Indenture”) by and between TIBCO and U.S. Bank National Association, as trustee relating to the issuance by TIBCO of $600 million aggregate principal amount of its 2.25% Convertible Senior Notes due 2032 (the “Notes”). The Indenture and the form of global note are filed as Exhibit 4.1 and Exhibit 4.2, respectively, to this Current Report on Form 8-K. The Notes bear interest at a rate of 2.25% per year on the principal amount, accruing from April 23, 2012. Interest is payable semiannually in arrears in cash on May 1 and November 1 of each year, beginning on November 1, 2012. The Notes will mature on May 1, 2032, subject to earlier repurchase, redemption or conversion.

The Notes are convertible at an initial conversion rate of 19.7750 shares of TIBCO’s common stock, par value $0.001 per share (the “Common Stock”), per $1,000 principal amount of Notes. This is equivalent to an initial conversion price of approximately $50.57 per share of common stock. Holders may only convert Notes at any time prior to the close of business on the business day immediately preceding February 1, 2032, and other than during the period from, and including, February 1, 2017 to the close of business on the business day immediately preceding May 5, 2017, under the following circumstances: (1) if the Notes are called for redemption, at any time prior to the close of business on the business day immediately preceding the redemption date; (2) during any fiscal quarter commencing after the fiscal quarter ending on September 2, 2012 (and only during such fiscal quarter), if the last reported sale price of the Common Stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (3) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of a share of Common Stock and the conversion rate on each such trading day; and (4) upon the occurrence of specified corporate events. On and after February 1, 2017 to the close of business on the business day immediately preceding May 5, 2017, and on or after February 1, 2032 until the close of business on the business day immediately preceding the maturity date, holders may convert Notes at any time, regardless of the foregoing circumstances. If a holder elects to convert its Notes in connection with a make-whole change in control, as that term is defined in the Indenture, TIBCO will, in certain circumstances, pay a make-whole change in control premium by increasing the conversion rate for Notes converted in connection with such make-whole change in control.

TIBCO may not redeem the Notes prior to May 5, 2017. On or after May 5, 2017, TIBCO may redeem for cash all or part of the Notes. The redemption price will equal 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, including any additional interest to, but excluding the redemption date. Holders may require TIBCO to repurchase all or a portion of their Notes on May 5, 2017, May 1, 2022 and May 1, 2027 at a cash repurchase price equal to 100% of the principal amount, plus accrued and unpaid interest to, but excluding, the repurchase date.

In the event of a fundamental change, as defined in the Indenture, the holders may require TIBCO to repurchase for cash all or a portion of their Notes at a repurchase price equal to 100% of the principal amount of the Notes, plus accrued and unpaid interest to, but excluding, the repurchase date.

Upon conversion, TIBCO will deliver an amount of cash and a number of shares of Common Stock, if any, equal to the sum of the daily settlement amounts for each daily volume weighted average price in the 35 day observation period for such Note.

The Notes are TIBCO’s general, unsecured obligations and are effectively subordinated in right of payment to all of TIBCO’s existing and future secured debt, to the extent of the value of the assets securing such debt, and are structurally subordinated to all indebtedness and other liabilities of TIBCO’s subsidiaries. The Indenture does not limit the amount of indebtedness that TIBCO or any of its subsidiaries may incur.

The following events are considered “Events of Default,” which may result in the acceleration of the maturity of the Notes:

The summary of the foregoing transactions is qualified in its entirety by reference to the text of the Indenture and related global note, which are included as Exhibits 4.1 and 4.2, respectively, hereto and are incorporated herein by reference.

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The foregoing terms and conditions of the Notes and Indenture described in Items 1.01 and 3.02 of this Current Report on Form 8-K are incorporated herein by reference.

Item 3.02 Unregistered Sales of Equity Securities.

As described in Item 1.01 of this Current Report on Form 8-K, which is incorporated herein by reference, TIBCO issued $600,000,000 aggregate principal amount of Notes to the initial purchasers on April 23, 2012 in a private placement pursuant to exemptions from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”). The Notes are convertible into cash and shares of Common Stock, if any, as described above.

TIBCO offered and sold the Notes to the initial purchasers in reliance on the exemption from registration provided by Section 4(2) of the Securities Act. The initial purchasers are initially offering the Notes to “qualified institutional buyers” pursuant to the exemption from registration provided by Rule 144A under the Securities Act. TIBCO relied on these exemptions from registration based in part on representations made by the initial purchasers.

The Notes and Common Stock issuable upon conversion of the Notes, if any, have not been registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

Item 5.07. Submission of Matters to a Vote of Security Holders

On April 26, 2012, TIBCO’s stockholders voted on the following four matters and cast their votes as described below:

The following is a summary of the voting results for each matter presented to the stockholders:

Proposal I – Election of Directors

TIBCO’s stockholders elected six members to the Board of Directors to serve until TIBCO’s next annual meeting of stockholders or until their successors are duly elected and qualified as set forth below:

Proposal II – Approval of the amendment and restatement of TIBCO’s 2008 Equity Incentive Plan

TIBCO’s stockholders approved the amendment and restatement if TIBCO’s 2008 Equity Incentive Plan as set forth below:

Proposal III – Approval, on an advisory basis, of the compensation of TIBCO’s Named Executive Officers

TIBCO’s stockholders cast their votes with respect to the advisory vote on approval of the compensation of TIBCO’s Named Executive Officers as set forth below:

Proposal IV – Ratification of the Appointment of PricewaterhouseCoopers LLP as TIBCO’s Independent Auditors for the Fiscal Year Ending November 30, 2012

TIBCO’s stockholders ratified the appointment of PricewaterhouseCoopers LLP as TIBCO’s independent auditors for the fiscal year ending November 30, 2012 as set forth below:

Item 8.01 Other Events.

Common Stock

In connection with the sale of the Notes, on April 23, 2012, TIBCO repurchased 3,648,488 shares of its Common Stock at a price of $33.16 per share.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

The following exhibits are filed herewith:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: April 27, 2012

EXHIBIT INDEX