Paul Sikivie was born on January 8, 1983, in Florida, and grew up in Gainesville. He studied at the University of North Florida in Jacksonville, and his earliest documented recording comes out of that scene: a performance of Alex LoRe's "A Morning Walk," led by trumpeter Alex Nguyen, that the International Trumpet Guild collected on its 2009 two-disc anthology The Roads They've Taken, a survey of the winners of its Jazz Improvisation Competition from 1979 to 2008. The band on that track is the Jacksonville circle Sikivie came up in: Nguyen and Brandon Lee on trumpets, LoRe on alto, Jeremy Fratti on tenor, Matt Zettlemoyer on baritone, Rob Edwards on trombone, Joshua Bowlus on piano and Ben Adkins on drums. Lee would still be on Sikivie's records sixteen years later.

He moved to New York City in 2007 to study at Juilliard and stayed. His first widely circulated New York credit was as the bassist in drummer Matt Wilson's Christmas Tree-O, a trio with reed player Jeff Lederer whose one album Palmetto issued in 2010 and whose NPR Tiny Desk Concert the same year put the group in front of a general audience. Trumpeter Mike Cottone's self-released Just Remember followed in 2011, and in March 2012 Plastic Sax issued Ted Nash's The Creep, a pianoless quartet of Nash on alto, Ron Horton on trumpet, Sikivie and drummer Ulysses Owens.

The association that defined his next decade began around 2010, when he took the bass chair in pianist Aaron Diehl's trio. That trio became the working band behind singer Cecile McLorin Salvant, and Sikivie is the album-wide bassist on For One to Love (Mack Avenue, September 2015), which won the Grammy for Best Jazz Vocal Album, and on nearly every track of the double album Dreams and Daggers, recorded at the Village Vanguard on September 9, 10 and 11, 2016 and at the DiMenna Center that December, released September 29, 2017, and awarded the same Grammy. On Dreams and Daggers he did more than play: he wrote the string arrangements that set the Catalyst Quartet against the piano trio on six of the album's pieces, the clearest evidence of the turn toward composition and arranging he dates to 2015. He also plays on Diehl's own The Vagabond (recorded February 4 to 6, 2019, released February 2020), and stayed in Salvant's orbit after the fixed touring trio wound down, taking bass, electric bass and Korg Mono/Poly synthesizer on Ghost Song (Nonesuch, 2022) and bass on Melusine (Nonesuch, 2023).

Running alongside that has been a second, harder-swinging body of work centered on the New York Smalls and Mezzrow scene and on Cory Weeds's Vancouver label Cellar Live. Sikivie is the bassist on Johnny O'Neal's Live at Smalls, cut at the club on June 16, 2013 with drummer Charles Goold and issued by SmallsLIVE in 2014, the record that marked O'Neal's return to New York. With tenor saxophonist Grant Stewart and drummer Phil Stewart he formed a standing pianoless trio that recorded Trio in New York on November 10, 2014 and Roll On at a house in Toronto in 2017. He played on and engineered Phil Stewart's Introducing Phil Stewart: Melodious Drum (recorded July 2, 2017), and returned to the Cellar orbit for Michael Weiss's Homage (recorded in Vancouver, April 2, 2023) and Grant Stewart's Next Spring (recorded November 2024). Trumpeter Joe Magnarelli's Concord, cut in February 2024 and issued by SteepleChase in 2025, bills Sikivie in equal type with Magnarelli, pianist Victor Gould and drummer Rodney Green. He has also spent a good deal of time behind singers other than Salvant, including the vocal trio Duchess, whose 2015 Anzic debut paired him with Matt Wilson, and Argentine singer Anita Donndorff, on six of the nine tracks of Thirsty Soul (Fresh Sound New Talent, 2025).

His own debut as a leader arrived on September 1, 2020: I'm in the Mood for Love, five tracks self-released on his Prismatic Spectacular imprint, which he arranged, produced and partly wrote. Rather than a fixed band, he cycled a small cast through the program, pairing tenor saxophonist Stephen Riley and trumpeter Brandon Lee across four tracks, adding David Gibson's trombone and Caleb Curtis's alto for the two four-horn arrangements, and reserving the last two tracks for a piano trio with Johnny O'Neal. Two of the five, "Bleeful Gounce" and "Rile's Wiles," are his own. In October 2020, at Big Orange Sheep Studios in Brooklyn, he and O'Neal recorded three duo performances that became one LP side of The Complete Orange Hours, a Diggers Factory double album of four unrelated duos issued in 2021 in a numbered edition of 450, and were separately released as their own single on LP345 Records that June.

Sikivie is a timekeeper first, and the records bear that out: the assignments he keeps getting are the ones where the bass has to hold a room together without a safety net, whether that is a pianoless quartet on Ted Nash's The Creep, a pianoless tenor trio with the Stewarts, an unaccompanied duo with a pianist as loose and conversational as Johnny O'Neal, or a singer working at whisper volume at the Village Vanguard. The writing he has done since 2015 sits at an unusual angle to that reputation. His string arrangements on Dreams and Daggers do not simply cushion the trio, they thread the Catalyst Quartet through it as a fifth and sixth voice, and his own leader date is built on a rotating instrumentation, four horns down to a piano trio, rather than a single band sound. The engineering and production credits point the same way: he mixed Trio and Roll On, recorded and mixed Phil Stewart's Melodious Drum, and produced and played synthesizer on the opening track of Salvant's Ghost Song, a record about as far from a hard-bop rhythm section date as her catalogue goes.