Michael John Sullivan (born September 22, 1939) is an American lawyer and politician who served as the 29th Governor of Wyoming from 1987 to 1995, and United States Ambassador to Ireland from 1998 to 2001, as a member of the Democratic Party.

He practiced law and became involved in local politics with his service on the Natrona County Memorial Hospital board.

Sullivan won in the 1986 and 1990 gubernatorial elections despite being outspent both times by Pete Simpson and Mary Mead.

He unsuccessfully ran for a seat in the United States Senate in the 1994 election before being appointed as the ambassador to Ireland by President Bill Clinton.

[13] In 1974, Sullivan was speculated as a possible nominee for Wyoming's Attorney General by Governor-elect Edgar Herschler.

[23] On March 20, Sullivan announced that he would seek the Democratic nomination at a press conference inside his house in Casper.

[24] Teno Roncalio, who served in the United States House of Representatives, supported Sullivan and was selected as an honorary chairman of his campaign.

[28] In the primary, Sullivan defeated Pat McGuire, Keith Goodenough, and Al Hamburg after spending $102,219.

The Republican's central committee held a meeting in 1989 to reduce the size of the primary field of candidates.

[44] Mary Mead won the Republican nomination after every candidate except for Nyla Murphy dropped out and endorsed her.

[46] He defeated Mead[47][35] and Sullivan's margin of victory was the largest for any governor in Wyoming's history at the time.

[50][51][52] He criticized the leadership of the Republicans in the state house in 1988 for denying committee chair positions to Representatives Murphy and Mary Odde due to them not supporting an attempt to override one of Sullivan's vetoes.

[60][61][62] He attempted to reappoint Carrol Orrison to the Wyoming Board of Equalization, but the state senate rejected his nomination.

[65] Sullivan was selected to replace Dave Freudenthal as the chairman of the Economic Development and Stabilization Board on January 21, 1987.

He was considered as a candidate for Ambassador to the Holy See to replace Raymond Flynn, but that position was given to Lindy Boggs instead.

[99] His nomination was approved by the United States Senate on October 21 and he was sworn in at a ceremony in the Indian Treaty Room on December 8.

[108] During the 2008 Democratic presidential primaries, he supported Hillary Clinton for the nomination and was appointed onto a Wyoming steering committee for her campaign on February 28, 2008.

[112] In 1987, Sullivan stated that "we didn't get any great support or reason for optimism" about the possibility of an oil import tax being implemented by Reagan after attending the National Governors Association.

[114] The National Governors Association voted thirty to five in favor of giving its support to CUSFTA, with Sullivan against.

[118][119] Sullivan asked W. Graham Claytor Jr. to restore Amtrak's passenger service through Wyoming after the line was altered to travel through Colorado instead in 1983.

During his speech he criticized the Reagan administration as it "waffled and rationalized" over allegations of fraud committed by President Ferdinand Marcos during the 1986 Philippine presidential election.

[123] In October, he stated that he would accept the removal of missiles from Wyoming as a part of an arms agreement with the Soviet Union as "if we can secure world peace, we can't be concerned about what effect it may have on our short-term economic development prospects.

[132] He and fellow governors Clifford Hansen, Stanley K. Hathaway, and Jim Geringer opposed ballot proposals during the 1996 election that would institute term limits in the state legislature.

[140] He opposed legislation that would prohibit children with AIDS from attending school and said that experts should make decisions about individual cases.

[144] In 1992, he stated that he would not grant clemency to convicted murderer Mark Hopkinson despite the American Civil Liberties Union, Wyoming Public Defender Leonard Munker, Gerry Spence, who led the prosecution against Hopkinson, and Marjorie Coggeshall, a relative of the murder victims, asking for clemency.

[154][155] He stated that legislation by House Minority Leader H. L. Jensen to lower the drinking age from twenty-one to nineteen was "the silliest thing I've heard in a long time".

[164] Sullivan criticized the Gramm–Rudman–Hollings Balanced Budget Act for "cutting and carving without recognition of needs and the merits of programs".

[167][168] Wyoming Senate Democratic Minority Whip John Fanos criticized Sullivan in 1992 for not having the leadership abilities to stop budget cuts and encourage tax increases.

[169] On March 15, 1994, Sullivan signed the 1995–1996 budget into law, but used his line-item veto against thirteen parts of the legislation.