Aldon Smith has the most sacks by a rookie linebacker, with 14 sacks in 2011.

which middle linebacker rookie has the most sacks in a season
Interpreted as:
Which middle linebacker rookie has the most defensive sacks in a season?
2011Smith2018Chubb2003Suggs1986Haley2011Miller1997Boulware2006Wimbley1983Maxwell2009Matthews2005Merriman1991Croel1989Thomas2001Bell1993Slade1990Wallace2017Lawson1987Bennett2015Smith2005Ware2000Urlacher1990Francis1986Harris2019Burns14.012.012.012.011.511.511.011.010.010.010.010.09.09.09.08.58.58.08.08.08.08.07.5
NAMESEASONTMGPSCKTKLASTCOMBSCKYINTINT YDSINT TDFFFRFR TD
Aldon SmithAldon Smith2011SFSF1614.031637104.5000210
Bradley ChubbBradley Chubb2018DENDEN1612.041196083000210
Terrell SuggsTerrell Suggs2003BALBAL1612.019827971110640
Charles HaleyCharles Haley1986SFSF1612.018020
Von MillerVon Miller2011DENDEN1511.550146477000200
Peter BoulwarePeter Boulware1997BALBAL1611.500000
Kamerion WimbleyKamerion Wimbley2006CLECLE1611.044186259.5000130
Vernon MaxwellVernon Maxwell1983BALBAL1611.0131020
Clay MatthewsClay Matthews2009GBGB1610.037145163000131
Shawne MerrimanShawne Merriman2005SDSD1510.043145761000200
Mike CroelMike Croel1991DENDEN1310.000000
Derrick ThomasDerrick Thomas1989KCKC1610.000010
Kendrell BellKendrell Bell2001PITPIT169.069138284000100
Chris SladeChris Slade1993NENE169.000010
Aaron WallaceAaron Wallace1990RAIRAI169.000000
Carl LawsonCarl Lawson2017CINCIN168.51061657000000
Cornelius BennettCornelius Bennett1987BUFBUF88.500000
Preston SmithPreston Smith2015WASWAS168.024113577000310
DeMarcus WareDeMarcus Ware2005DALDAL168.047115847000300
Brian UrlacherBrian Urlacher2000CHICHI168.0219010
James FrancisJames Francis1990CINCIN168.0117100
Tim HarrisTim Harris1986GBGB168.000010
Brian BurnsBrian Burns2019CARCAR167.51962534000111
Ryan KerriganRyan Kerrigan2011WASWAS167.542226455.5191400
Leroy HillLeroy Hill2005SEASEA157.552217336.5000200
StatMuse has season-level data for sacks going back to the 1982 season.