The 1999–2000 season was Ulster Rugby's fifth season under professionalism, and Harry Williams's second season as head coach.
They competed in the Heineken Cup and the IRFU Interprovincial Championship.
Ahead of the new season, Williams signed Paddy Johns, Simon Best, Niall Malone, Tyrone Howe, Spencer Bromley and Riaz Fredericks to full-time contracts.
Mark McCall retired as a player, and was appointed assistant coach.
[1] In the Heineken Cup, Ulster finished bottom of their pool.
They came second in the Interprovincial Championship, qualifying for next season's Heineken Cup.
Tony McWhirter was Ulster's Player of the Year.
Plans for a Celtic League, featuring the Irish provinces alongside teams from Scotland and Wales, were mooted.
This would give the provinces a 12-game league schedule, alongside six Interpros and at least six Heineken Cup matches, and mean contracted players would no longer be available for their All-Ireland League clubs, but play exclusively for their provinces.
This plan would not materialise for another few seasons.
Props Hookers Locks Back row Scrum-halves Fly-halves Centres Wings Fullbacks 1.
Justin Fitzpatrick, 2.
Replacements: Simon Best (for Veitayaki), Tyrone Howe (for Malone), Mark Edwards (for Bell), Mark Blair (for Longwell), Derek Topping (for O'Cuinneagain).
Justin Fitzpatrick, 2.
Replacements: Niall Malone (for J.
Bell, 39), Derek Topping (for Miller, 40), Tyrone Howe (for Malone, 42), Gary Longwell (for Johns, 78).
Replacements: Dion O'Cuinneagain (for McWhirter, 22), Richard Weir (for Clarke, 27), Stephen Bell (for Edwards, 54), Gary Longwell (for Johns, 68), Tyrone Howe (for J.
Topping, 77), Niall Malone (for Mason, 78).
Replacements: Simon Best (for Veitayaki), Stephen McKinty (for Miller).
Replacements: Gary Longwell (for Blair, 78).
Replacements: Tony McWhirter (for Miller, 40), Mark Blair (for Ward, 55), Simon Best (for Veitayaki, 68), Jan Cunningham (for J.
Replacements: Mark Blair (for Longwell, 59), Eric Miller (for McWhirter, 59), Riaz Fredericks (for Howe, 66), Niall Malone (for Humphreys, 66), Simon Best (for Leslie, 71).
Replacements: Tony McWhirter (for Miller, 48), Riaz Fredericks (for Cunningham, 58), Mark Blair (for Longwell, 60), Richard Weir (for Clarke, 83).
Replacements: Richard Weir (for Clarke, 23), Tony McWhirter (for Miller, 55), Mark Blair (for Longwell, 50), Simon Best (for Leslie, 66), Riaz Fredericks (for Cunningham, 71).
Replacements: Paddy Johns (for Blair, 46), Eric Miller (for O'Cuinneagain, 52), Lewis Johnston (for Best, 63), Jan Cunningham (for Topping, 72).
Replacements: Stephen McKinty (for Miller, 40), Gary Longwell (for Blair, 60), Niall Malone (for Humphreys, 67).
Replacements: Gary Leslie (for Irwin, 52), Allen Clarke (for Humphreys, 55), Stephen Bell (for Edwards, 63) 1.
Replacements: Stephen Ritchie (for Weir, 78'), Rab Irwin (for Leslie, 19'), Charlie Simpson (for Blair, 79'), Stuart Duncan (for McKinty, 71'), Andrew Matchett (for Edwards, 66'), Bryn Cunningham (for Malone, 35'), Tyrone Howe (for Coulter, 40').
Replacements: Gordon D'Arcy (for O'Shea, 71'), Jonathan Bell (for O'Driscoll, 68'), Justin Fitzpatrick (for Clohessy, 71), Jeremy Davidson (for O'Kelly, 68'), Eric Miller (for Corkery, 63') Andy Ward (for Dawson, 63').
The Ulster Rugby Awards ceremony was held on 18 May 2000 at the La Mon House Hotel.